PyTek Documentation

PyTek provides a python API for interacting with Tektronix oscilloscopes over a serial interface. It currently supports some basic commands for the TDS3k series of DPO’s, especially capturing waveforms and screen shots from the device.

Note

Serial Port not Included

PyTek relies on a thirdparty serial port for communications, specifically one that matches the pyserial API. It is recommended that you simply use pyserial itself.

Getting Started

To get started, try the README, or for complete documentation, check out the pytek module API documentation page.

Documentation Contents:

README

PyTek provides a python API for interacting with Tektronix oscilloscopes over a serial interface. It currently supports some basic commands for the TDS3000 series of Digital Phosphor Oscilloscopes, especially capturing waveforms and screen shots from the device.

Note

Serial Port not Included

PyTek relies on a thirdparty serial port for communications, specifically one that matches the pyserial API. It is recommended that you simply use pyserial itself.

Page Contents

tl;dr

What?

A python package that gives you an API for interacting with supported Tektronix oscilloscopes over a serial interace.

Install?
$ pip install pytek

Or, from source:

$ python setup.py install
Serial?

We don’t provide a serial port implementation. We suggest, pyserial:

$ pip install pyserial
Examples?
>>> from serial import Serial
>>> from pytek import TDS3k
>>>
>>> port = Serial("COM1", 9600, timeout=1)
>>> tds = TDS3k(port)
>>>
>>>
>>> # Make the scope identify itself.
...
>>> tds.identify()
'TEKTRONIX,TDS 3034,0,CF:91.1CT FV:v2.11 TDS3GM:v1.00 TDS3FFT:v1.00 TDS3TRG:v1.00'
>>>
>>>
>>>
>>> # Capture waveform data
...
>>> waveform = tds.get_waveform(start=100, stop=109)
>>> waveform
<generator object <genexpr> at 0x0238B8A0>
>>
>>> for x,y in waveform:
...     print x, y
...
-0.0045 -0.16
-0.004499 -0.04
-0.004498 -0.04
-0.004497 -0.12
-0.004496 -0.12
-0.004495 -0.08
-0.004494 -0.12
-0.004493 -0.16
-0.004492 -0.2
-0.004491 -0.08
>>>
>>> tds.x_units()
's'
>>> tds.y_units()
'V'
>>>
>>>
>>>
>>> # Grab a screen shot (this will take a few minutes).
...
>>> ofile = open("screenshot.tiff", "wb")
>>> tds.screenshot(ofile, "tiff")
>>>
>>>
>>>
>>>
>>> #Fin.
...
>>> tds.close()
>>>
Dependencies?

You’ll need a serial port interface. See the “Serial?” section, above.

To build the sphinx docs from source (as is), you’ll need the sphinx_rtd_theme:

$ pip install sphinx_rtd_theme
Extras?

PyTek package includes the following extras (optional installs):

serial
Adds pyserial package as a requirement, the recommended serial port interface.
docs
Adds sphinx_rtd_theme package as a requirement, needed for building sphinx docs.

Misc.

Contact Information

This project is currently hosted on bitbucket, at https://bitbucket.org/bmearns/pytek/. The primary author is Brian Mearns: you can contact Brian through bitbucket at https://bitbucket.org/bmearns.

pytek module

This is the top level module of the PyTek package. It provides classes for interfacing with various Tektronix oscilloscopes over a serial interface.

Most classes in this module are based on a specific series of devices, based on the serial interface supported by the devices. There is currently only one class provided, TDS3k which supports the TDS 3000 series of devices.

Note

Serial Port not Included

pytek relies on a thirdparty serial port for communications, specifically one that matches the pyserial API. It is recommended that you simply use pyserial itself.

class pytek.TDS3k(port)[bitbucket][source]

Bases: pytek.util.Configurable

The TDS3k class provides functions for interacting with the TDS 3000 series of DPO’s from Tektronix. Documentation on this interface is available from Tektronix at this link.

Instances of this class are instantiated by passing in a serial port object, which supports the pyserial interface. This is the port that the object will use for interacting with the device. Configuration of this port depends on your device and your serial port implementation. Typical settings for RS232 are 9600 baud.

Example:

#Import class
from pytek import TDS3k

#Import pyserial
import serial

port = serial.Serial("COM1", 9600, timeout=1)
tds = TDS3k(port)

# ... do stuff with the tds object.

#Closes the object's port.
tds.close()

Warning

Serial Port Timeout

It is very important that you specify a timeout on your serial port. The get_response method (used by things like screenshot and get_curve) continue to read data until a read timesout, so if there is no timeout, it will never return.

ID_REGEX = <_sre.SRE_Pattern object at 0x2a41150>[bitbucket]

The regular expression used to match the start of the identify string, for sanity_check.

r'^TEKTRONIX,TDS 3\d{3},'
close()[bitbucket][source]

Closes the object’s port by invoking it’s close method.

The object itself is not affected by this so if you call any methods that try to communicate over the port, it will be trying to communicate over a closed port.

send_command(command[, arg1[, arg2[, ...]]])[bitbucket][source]

Sends a command and any number of arguments to the device. Does not wait for response.

See also

  • send_query - To send a query and get a one-line response.
send_query(query)[bitbucket][source]

Sends a query to the device and reads back one line, returning that line (stripped of trailing whitespace).

A ‘?’ and a linebreak are automatically appended to the end of what you send.

E.g.:

>>> tek.send_query("*IDN")
'TEKTRONIX,TDS 3034,0,CF:91.1CT FV:v2.11 TDS3GM:v1.00 TDS3FFT:v1.00 TDS3TRG:v1.00'
>>>

Warning

This method turns off header echoing from the device. I.e., it sends "HEADER OFF" before anything else (through the headers_off method). If you’re expecting headers to be on subsequently, you will need to turn them on with "HEADER ON", or with the headers_on method.

query_quoted_string(query)[bitbucket][source]

Like send_query, but expects a quoted string as a response, and strips the quotes off the response before returning. Raises a ValueError if the response is not quoted.

get_response()[bitbucket][source]

Simply reads data from the object’s port, one byte at a time until the port timesout on read. Returns the data as a str.

Waits indefinitely for the first byte.

headers_off()[bitbucket][source]

Sends the "HEADER OFF" command to the device, to disable echoing of headers (command names) in query responses from the device. Most methods that query the device will cause this to be sent. You can turn it back on with headers_on, or by sending the "HEADER ON" command.

headers_on()[bitbucket][source]

Sends the "HEADER ON" command to the device. See headers_off for details.

identify()[bitbucket][source]

Convenience function for sending the "*IDN" query, with send_query, and returning the response from the device. This provides information about the device including model number, options, application modules, and firmware version.

See also

  • sanity_check uses the response from this method to determine if the connected device appears to a supported model.
sanity_check()[bitbucket][source]

Does a sanity check on the device to make sure that the way it identifies itself matches the expected response. Returns True if the sanity check passes, otherwise False.

The device does not actually enforce this test, and will not perform it automatically (i.e., only if you call this method). This is for your sake so you don’t waste time on a device that isn’t compatible.

See also

force_sanity()[bitbucket][source]

Does the sanity_check on the device, and raises an Exception if the check fails.

acquire_state([val])[bitbucket][source]

Configures or queries the value of the ACQUIRE:STATE setting on the device. If a value is given, then the setting is configured to the given value. If the value is None (the default), then the setting is queried and the value is returned.

For queries, return True or False:

  • True if the device replies with any of the following: "1", "ON", "RUN"
  • False otherwise.

For configuring, if val evaluates as True, causes "1" to be sent to the device. Any other value for val causes "0" to be sent.

The ACQUIRE:STATE setting is related to the “RUN / STOP” button on the device, and it basically configures whether the device is actually acquiring data or not.

acquire_single([val])[bitbucket][source]

Configures or queries the value of the ACQUIRE:STOPAFTER setting on the device. If a value is given, then the setting is configured to the given value. If the value is None (the default), then the setting is queried and the value is returned.

For queries, return True or False:

  • True if the device replies with any of the following: "SEQ", "SEQUENCE"
  • False otherwise.

For configuring, if val evaluates as True, causes "SEQ" to be sent to the device. Any other value for val causes "RUN" to be sent.

The ACQUIRE:STOPAFTER setting is related to the “single sequence” button on the device. If True, then when the device is set to acquire (e.g., by passing True to acquire_state), it will only acquire a single sequence, and then stop automatically. Otherwise, it will continue to acquire until it is stopped.

trigger()[bitbucket][source]

Force the device to trigger, assuming it is in READY state (see trigger_state).

This sends the TRIGGER FORCE command to the device.

trigger_auto([val])[bitbucket][source]

The TRIGGER:A:MODE is related to the “AUTO” and “NORMAL” selections in the Trigger menu. If set to True, the trigger is in “AUTO (Untriggered roll)” mode, in which the device automatically generates a trigger if none is detected.

Otherwise, the device is in “NORMAL” mode, in which the device waits for a valid trigger.

val = 'trigger'[bitbucket]
trigger_state()[bitbucket][source]

Returns a string indicating the current trigger state of the device. This queries the TRIGGER:STATE setting on the device.

The following list gives the possible return values:

  • auto - indicates that the oscilloscope is in auto mode and acquires data even in the absence of a trigger (see trigger_auto).
  • armed - indicates that the oscilloscope is acquiring pretrigger information. All triggers are ignored in this state.
  • ready - indicates that all pretrigger information has been acquired and the oscilloscope is waiting for a trigger.
  • save - indicates that acquisition is stopped or that all channels are off.
  • trigger - indicates that the oscilloscope has seen a trigger and is acquiring the posttrigger information.
get_waveform_preamble()[bitbucket][source]

Queries the waveform preamble from the device, which details how a waveform or curve will be transferred from the device based on the current settings (as with get_curve or get_waveform, though note that both of those functions alter settings based on provided parameters, before retrieving the data).

Returns a dictionary of preamble values.

Example:

>>> wfm_preamble = tds.get_waveform_preamble()
>>> for k, v in wfm_preamble.iteritems():
...     print k, ":", repr(v)
...
byte_order : 'MSB'
binary_format : 'RP'
x_incr : 1e-06
y_scale : 0.08
number_of_points : 10000
y_unit : '"V"'
encoding : 'BIN'
y_zero : 0.0
point_format : 'Y'
waveform_id : '"Ch1, DC coupling, 2.0E0 V/div, 1.0E-3 s/div, 10000 points, Sample mode"'
x_units : '"s"'
y_offset : 128.0
bits_per_sample : 8
bytes_per_sample : 1
pt_offset : 0
xzero : -0.0045
>>>
get_curve(source='CH1', double=True, start=1, stop=10000, preamble=False, timing=False)[bitbucket][source]

Queries a curve (waveform) from the device and returns it as a set of data points. Note that the points are simply unsigned integers over a fixed range (depending on the double parameter), they are not voltage values or similar. Use get_waveform to get scaled values in the proper units.

Warning

Note that this method will set waveform preamble and data parameters on the device, which have a persistent effect which could alter the behavior of future commands.

If preamble or timing are True, returns a tuple: (preamble_data, data, timing_data), where the preamble_data and timing_data are only present if the corresponding flag is set.

If neither preamble nor timing is True, then just returns data as the sole argument (i.e., data, not (data,)).

In either case, data will be a sequence of data points for the curve. If the double parameter is True (the default), data points are each double-byte wide, in the range from 0 through 65535 (inclusive). This gives you maximum resolution on your data, but takes longer to transfer. Also note that the device does not necessarily have 16 bits of precision in measurement, but data will be left-aligned to the most significant bits.

If double is False, then the data points are single-byte each, in the range from 0 through 255 (inclusive).

Regardless of double, the minimum value corresponds to one vertical division below the bottom of the screen, and the maximum value corresponds to one vertical division above the top of the screen.

Parameters:
  • source (str) – Optional, specify the channel to copy the waveform from. Default is "CH1".
  • double (bool) – Optional, if True (the default), data points are transferred 16-bits per point, otherwise they are transferred 8-bits per point, which may cut off least significant bits but will transfer faster.
  • start (int) – Optional, the data point to start at. The waveforms contains up to 10,000 data points, the first point is 1. The default value is 1. If you set this param to None, it has the same effect as a 1.
  • stop (int) – Optional, the data point to stop at. See start for details. The default value is 10,000 to transfer the entire waveform. If you set this to None, it has the same effect as 10,000.
  • preamable (bool) – Controls whether or not the curve’s preamble is included in the return value. The curve’s preamble is not the same as the waveform preamble that configures the data. The curve’s preamble is a string that is transmitted prior to the curve’s data points. I’m honestly not sure what it is, but it contains a number which seems to increase with the number of data points transferred.
  • timing (bool) – Controls whether or not timing information is included in the return value. Timing gives the number of seconds it took to transfer the data, as a floating point value.
get_waveform(source='CH1', double=True, start=1, stop=10000, preamble=False, timing=False)[bitbucket][source]

Similar to get_curve, but uses waveform premable data to properly scale the received data.

If preamble or timing are True, returns a tuple: (preamble_data, data, timing_data), where the preamble_data and timing_data are only present if the corresponding flag is set.

If neither preamble nor timing is True, then just returns data as the sole argument (i.e., data, not (data,)).

data is a sequence of two tuples, giving the X and Y value for each point, in order across the X-acis from left to right. These are properly scaled based on the waveform settings, Giving, for instance, a value in Volts versus Seconds. Check x_units and y_units to get the actual units.

get_num_points()[bitbucket][source]

Queries the number of points that will be sent in a waveform or curve query, based on the current settings.

This is relevant to functions like get_waveform and get_curve, but note that those functions set the DATA:START and DATA:STOP configuration options on the device based on provided parameters, thereby effecting the number of points.

y_units()[bitbucket][source]

Returns a string giving the units of the Y axis based on the current waveform settings.

Example:

>>> tds.y_units()
'V'
>>>
x_units()[bitbucket][source]

Returns a string giving the units of the X axis based on the current waveform settings. Possible values include 's' for seconds and 'Hz' for Hertz.

Example:

>>> tds.x_units()
's'
>>>
screenshot(ofile=None, fmt='RLE', inksaver=True, landscape=False)[bitbucket][source]

Grabs a hardcopy/screenshot from the device.

If ofile is None (the default), simply returns the data as a string. Otherwise, it writes the data to the given output stream.

Parameters:
  • fmt (str) – Optional, specify the format for the image. Valid values will vary by device, but will be a subset of those listed below. The default is “RLE” which gives a Windows Bitmap file.
  • inksaver (bool) – Optional, if True (the default), puts the device into hardcopy-inksaver mode, in which the background of the graticular is white, instead of black. If False, sets the device to not be in inksaver mode.
  • landscape (bool) – Optional, if False (the default), the image will be in portrait mode, which is probably what you want. If True, it will be in landscape mode, which generally means the image will be rotated 90 degrees.

Possible supported formats:

The following is a list of the formats that may be supported, but individual devices will only support a subset of these. To see if your device supports a format, use check_img_format.

  • TDS3PRT - For the TDS3000B series only, sets format for the TDS3PRT plug-in thermal printer.
  • BMP - Grayscale bitmap. This is uncompressed, and very large and slow to transfer.
  • BMPColor - Colored bitmap. Uncompressed, very large and slow to transfer.
  • DESKJET - For the TDS3000B and TDS3000C series only, formatted for HP monochrome inkjet printers.
  • DESKJETC - For the TDS3000B and TDS3000C series only, formatted for HP color inkjet printers.
  • EPSColor - Colored Encapsulated PostScript.
  • EPSMono - Monochrome Encapsulated PostScript.
  • EPSON - For the TDS3000B and TDS3000C series only, supports Epson 9-pin and 24-pin dot matrix printers.
  • INTERLEAF - Interleaf image object format.
  • LASERJET - For the TDS3000B and TDS3000C series only, supports HP monochrome laser printers.
  • PCX - PC Paintbrush monochrome image format.
  • PCXcolor - PC Paintbrush color image format.
  • RLE - Colored Windows bitmap (uses run length encoding for smaller file and faster transfer).
  • THINKJET - For the TDS3000B and TDS3000C series only, supports HP monochrome inkjet printers.
  • TIFF - Tag Image File Format.
  • DPU3445 - Seiko DPU-3445 thermal printer format.
  • BJC80 - For the TDS3000B and TDS3000C series only, supports Canon BJC-50 and BJC-80 color printers.
  • PNG - Portable Network Graphics.

Note

The fatest transfer seems to be RLE, with TIFF close behind (transfer times are less than one minute at 9600 baud). BMP and BMPColor take a very long time (more than five minutes at 9600 baud).

check_img_format(fmt)[bitbucket][source]

Tests if a hardcopy image format is supported by the device. This simply sets the HARDCOPY:FORMAT configuration value to the given format, and checks to see if it comes back as the same format.

Return True if the format is supported, False otherwise.

Resets the HARDCOPY:FORMAT back to where it was before returning.

See also

screenshot

k = 'trig'[bitbucket]
seq = ['trigger', 'trig'][bitbucket]
pytek.TDS3xxx[bitbucket]

alias of TDS3k

pytek.util module

class pytek.util.Configurator(name, get=None, set=None, doc=None)[bitbucket][source]

Bases: object

The Configurator class creates helper objects that can be used to easily add methods to a class to configure and query a particular setting on the device.

The easiest way to understand it is by example. First, a stripped down usage example:

class MyDevice(object):

    __metaclass__ = Configurator.ConfigurableMeta

    @Configurator.config("FOO:BAR")
    def foobar(self, val):
        return val.lower()

    @foobar.setter
    def foobar(self, val):
        return val.upper()


    @Configurator.config
    def frobbed(self, val):
        return (val == "ON")

    @frobbed.setter
    def frobbed(self, val):
        return "ON" if val else "OFF"

And now, a more thorough example, expanded from this:

class MyDevice(object):

    #Make sure it uses the ConfigurableMeta class as its metaclass,
    # so Configurator objects in the class definition get replaced with
    # appropriate methods.
    __metaclass__ = Configurator.ConfigurableMeta

    #Just some ordinary instance attributes, which we will be the target of
    # our setting configuring and querying.
    __foobar = "TAZ"
    __frobbed = "OFF"

    #This is where the class actually implements sending command and queries.
    # The Configurator objects will call these methods.

    def send_command(self, name, arg):
        print "~~~> %s %s" % (name, arg)
        if name == "FOO:BAR":
            if not isinstance(arg, str):
                raise TypeError()
            if arg != arg.upper():
                raise ValueError()
            self.__foobar = arg

        elif name == "FROBBED":
            if arg not in ("ON", "OFF"):
                raise ValueError()
            self.__frobbed = arg

        else:
            raise KeyError()
            

    def send_query(self, name):
        print "???? %s" % name
        if name == "FOO:BAR":
            val = self.__foobar
        elif name == "FROBBED":
            val = self.__frobbed
        else:
            raise KeyError()
        print "    <<<< %s" % val
        return val


    #Now, define Configurators for each of our configurable settings.


    #First, for the FOO:BAR setting, which will be accessed through a
    # function called `foobar`.

    @Configurator.config("FOO:BAR")
    def foobar(self, val):
        #Translate a value returned by `send_query` into a value to return
        # to the calling code.
        return val.lower()

    @foobar.setter
    def foobar(self, val):
        #Translate a value provided by the calling code into a value that
        # will be passed to `send_command`.
        return val.upper()


    #Now, the FROBBED setting. We can use implicit named in the decorator
    # for this one.

    @Configurator.config
    def frobbed(self, val):
        '''
        +++
        Querying returns True for "ON", and False for "OFF".
        '''
        if val == "ON":
            return True
        if val == "OFF":
            return False
        raise ValueError(val)

    @frobbed.setter
    def frobbed(self, val):
        '''
        +++
        Valid values for configuring are True and False, or synonomously
        "ON" and "OFF".
        '''
        if val is True or val == "ON":
            return "ON"
        elif val is False or val == "OFF":
            return "OFF"
        raise ValueError()

With the above code, you could then do the following:

>>> dev = MyDevice()
>>> dev.foobar()
???? FOO:BAR
    <<<< TAZ
'taz'
>>>
>>> dev.foobar('razzle-dazzle')
~~~> FOO:BAR RAZZLE-DAZZLE
>>>
>>> dev.foobar()
???? FOO:BAR
    <<<< RAZZLE-DAZZLE
'razzle-dazzle'
>>>
>>>
>>> dev.frobbed()
???? FROBBED
    <<<< OFF
False
>>> dev.frobbed(True)
~~~> FROBBED ON
>>> dev.frobbed()
???? FROBBED
    <<<< ON
True
>>>
>>> dev.frobbed(False)
~~~> FROBBED OFF
>>> dev.frobbed()
???? FROBBED
    <<<< OFF
False
>>>
>>> dev.frobbed("ON")
~~~> FROBBED ON
>>> dev.frobbed()
???? FROBBED
    <<<< ON
True
>>>
>>> dev.frobbed("???")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "src\pytek\util.py", line 125, in config
    return self(device, val)
  File "src\pytek\util.py", line 116, in __call__
    self.configure(device, self.name, self.set(device, val))
  File "temp.py", line 94, in frobbed
    raise ValueError()
ValueError
>>>
>>>
>>> help(dev.foobar)
Help on method foobar in module pytek.util:

foobar(device, val=None) method of temp.MyDevice instance
    Configures or queries the value of the ``FOO:BAR`` setting on the device.
    If a value is given, then the setting is configured to the given value.
    If the value is `None` (the default), then the setting is queried and the value
    is returned.

>>>
>>> help(dev.frobbed)
Help on method frobbed in module pytek.util:

frobbed(device, val=None) method of temp.MyDevice instance
    Configures or queries the value of the ``FROBBED`` setting on the device.
    If a value is given, then the setting is configured to the given value.
    If the value is `None` (the default), then the setting is queried and the value
    is returned.


    Querying returns True for "ON", and False for "OFF".


    Valid values for configuring are True and False, or synonomously
    "ON" and "OFF".

>>>
>>>
Parameters:
  • name – Specifies the name of the setting accessed by this object. Should be either a callable object with a __name__ attribute, or a string. Strings will be used directly, callables will be filtered through func_to_name.
  • get (callable) – Optional: if given, passed to getter.
  • set (callable) – Optional: if given, passed to setter.
  • doc (callable) – Optional: if given, used as the value of the doc attribute.
DEFAULT_DOCTSTR = '\nConfigures or queries the value of the ``%(NAME)s`` setting on the device.\nIf a value is given, then the setting is configured to the given value.\nIf the value is `None` (the default), then the setting is queried and the value\nis returned.\n'[bitbucket]

A string used for default value of the doc attribute.

classmethod configure(device, name, val)[bitbucket][source]

The final method in this object used to configure the setting, given the raw value to be sent to the device. This is called by the __call__ method when appropriate.

This delegates to the send_command method of the given device.

Parameters:
  • device – The object on which the send_command will be invoked.
  • name (str) – The name of the setting, usually the value of the name attribute. This is the first arguments passed to send_command.
  • val (str) – The raw value to configure the setting to. This is the second argument passed to send_command.
classmethod query(device, name)[bitbucket][source]

The final method in this object used to query the setting, returning the raw value from the device. This is called by the __call__ method when appropriate.

This delegates to the send_query method of the given device.

Parameters:
  • device – The object on which the send_query will be invoked.
  • name (str) – The name of the setting, usually the value of the name attribute. This is the only arguments passed to send_query.
create_method(name)[bitbucket][source]

Creates a method with the given name which can be installed in a class to delegate to this object’s __call__ method. Sets the name of the method to name, and sets the docstr (__doc__) to the value of this object’s doc attribute.

This is used by ConfigurableMeta to replace Configurator instances in the classes dictionary with functions.

update_doc(func)[bitbucket][source]

If the given function has a docstrig (__doc__), then this object’s doc attribute is updated with it. Otherwise, it does nothing.

If func‘s docstr begins with '+++' alone on a line (any amount of leading and trailing whitespace), then the remainder of the docstring is appended to the existing docstring, instead of replacing it.

classmethod func_to_name(func)[bitbucket][source]

Derives a setting name from a function. The implementation here just uses the __name__ attribute of the given func, and then uses str.upper() to make it all upper case.

This is used in __init__ if the name is a callable object.

classmethod boolean(arg, **kwargs)[bitbucket][source]

A function decorator utility used to create a Configurator object which handles boolean settings. This ends up delegating to set_boolean to actually set up the get and set filters based on responses from the decorated function. All keyword arguments passed to this function are forwarded to set_boolean.

Similar to config, you can invoke this with implicit arguments or explicit arguments

For implicit arguments, you use this method as a function decorator directly, and the name to use is derived from the decorated function with func_to_name. In this mode, you can’t specify any additional arguments to pass to set_boolean.

For explicit arguments, you invoke this method directly, and it returns a function decorator. This allows you to pass in a string as the first argument to specify the name to use, as well as additional keyword arguments to be forwarded on to set_boolean.

classmethod config(arg)[bitbucket][source]

A function decorator utility used to create a Configurator object and a function decorator to configure its getter.

There are two way to invoke this, using implicit naming or explicit naming.

For implicit naming*, simply pass a function in directly, or use this function directly as a decorator. For instance:

@Configurator.config
def foobar(self, val):
    return val

The above code will create a new instance of cls (i.e., a Configurator object), and will pass the given function foobar in as the name parameter to the constructor. This in turn will use func_to_name to derive a value for the instance’s name attribute from the function, by default (i.e., in the base Configurator class), this is just the name of the function in all uppercase.

The function will also be passed to the instance’s getter method so that the foobar function becomes the instance’s get filter.

This method will then return the Configurator object itself, not the wrapped function.

The alternative is explicit naming, in which this function is not used as a function wrapper, but invoked to return a function wrapper. This gives you some added flexibility such as explitictly giving the name to use for the Configurator object. Otherwise, the behavior is essentially the same.

For instance:

@Configurator.config('BAZ:RUFFLE')
def foobar(self, val):
    return val

In this case, even though the wrapped function has the same name, "foobar", the created Configurator object will have a name of "BAZ:RUFFLE". Other than that, the effects are the same.

In either case, when code like this appears in a class definition, it means that class will have an attribute named foobar whose value is a Configurator object. If this class is using the ConfigurableMeta metaclass, then this attribute will be replaced by a proper method generated by the Configurator’s create_method method.

Also note that when the wrapped function is passed to the Configurator’s getter method, this method will also pass it to update_doc, so if the wrapped function has a docstring, the Configurator object’s doc attribute will be set accordingly. When the ConfigurableMeta gets a hold of it, the corresponding method it adds to the class will receive this docstr from the Configurator object.

Note that for the remainder of the class definition, you can use the generated Configurator object. For instance, you can follow up either of the above examples with the following:

@foobar.setter
def foobar(self, val):
    if val is False:
        return "OFF"
    return "ON"

Since at this point the foobar symbol is actually a Configurator object, you can use its other decorators such as setter and getter.

setter(func)[bitbucket][source]

A function wrapper which sets this object’s set attribute to the given function and passes the function to update_doc, then returns self.

The given function should take two arguments and return a string. The first argument will be the device on which the send_command method is invoked, the second argument will be the client supplied value they want to configure the setting to. The function should return a corresponding string which will actually be sent to the device.

getter(func)[bitbucket][source]

Like setter, but sets the object’s get attribute, used for querying the setting from the device.

This is a function wrapper which sets this object’s get attribute to the given function and passes the function to update_doc, then returns self.

The given function should take two arguments and return a string. The first argument will be the device on which the send_query method is invoked, the second argument will be the value returned from the device by send_query. The function should return a corresponding value which will be returned to the user to reflect the string returned by the device.

set_boolean(func, strict=False, default=False, nocase=False)[bitbucket][source]

Configures the objects set and get filters based on a boolean setting.

A boolean setting means the setting has a set of possible values that are partitioned into two subsets: true values and false values. On the python side, any value in these subsets corresponds to a value of True or False, respectively.

This method sets up the object to filter values accordingly, so that querying the setting always returns True or False, and configuring the setting can be done with True or False.

To do so, you have to pass in a function which can be evaluated immediately to get the set of true values and the set of false values. The function should take a single boolean argument, if the argument value is True, return the set of true values, otherwise, return the set of false values. The method will then create appropriate set and get filters based on these values and the other parameters passed into this function (see below).

The sets of true values and false values returned by func must be sequences. The first value in each sequence will be used as the canonical value, meaning the ones that will actually be passed to the device for the corresponding value. All other values in the sets will be acceptable responses from the device for queries, and will result in the corresponding boolean value being returned to the caller.

See also

boolean

Parameters:
  • func (callable) – This function will be called twice, immediately. Once with a value of True, which should return a sequence of true values; and once with a value of False, which should return a sequence of false values.
  • strict (bool) –

    Optional, default is False. If True, then the generated set and get filters will be strict about values. The set filter will only accept boolean values, and will raise a TypeError otherwise. The get filter will only accept values from the true- and false- value sets, and will raise a ValueError if the device returns anything else.

    If the value of the parameter is False, the generated functions are not as strict, and will not raise exceptions for unrecognized values (the way it handles unrecognized values depends on the value of the default parameter). For the non-strict set filter, values are simply evaluated as bools to choose which value to send.

  • default (bool) – Optional, default value is False. This is only used if strict is False, in which case it determines the default value when an unrecognized value is encountered.
  • nocase (bool) – Optional, default value is False. If True, then values are considered case-insensitive.
class ConfigurableMeta[bitbucket][source]

Bases: type

This is a meta class that can be added to classes to more easily support the use of Configurator objects as pseudo-methods.

The meta class extends the __new__ function to find all instances of Configurator in the class’s dictionary, and replace it with a method created by the Configurator’s create_method method.

See the example code in the documentation for Configurator for an example.

x.__init__(...) initializes x; see help(type(x)) for signature

class pytek.util.Configurable[bitbucket][source]

Bases: object

Just a simple base classes that uses ConfigurableMeta as the metaclass.

x.__init__(...) initializes x; see help(type(x)) for signature

pytek.version module

The version module provides version numbering for the entire PyTek package.

Page Contents

Versioning

The PyTek packages uses a five part version number, plus an incremental release number. Either the version number or the release number can be used to identify a released version of the code.

Version Number

The version number is a four part dotted number, with an optional tag on the end. Formally, a version number looks like:

version number ::=  <Major>.<minor>[.<patch>[.<semantic>]][-[x-]<tag>]

With each new released version of the code, exactly one of the four numbers will increase, and any numbers to its right will reset to 0.

The easiest way to understand version numbers is from the perspective of someone who has written client code: i.e., code that makes use of a particular version of the PyTek library. From this perspective, the version number indicates whether or not your client code can be expected to work with different versions of PyTek.

Major Version

The <Major> component is the major version number, and it describes backward compatibility. Going to a newer version of PyTek, your code should continue to work as long as the major version doesn’t change.

The major version is changed only when something is removed from the PyTek public interface. For instance, if a function is no longer supported, the major version number would have to increase, because client code which relied on that function would no longer work.

The major version number can be accessed through the MAJOR member of this module.

Minor Version

The <minor> component is the minor version number, and it describes forward compatibility: Going to an older version of PyTek, your code will continue to work as long as the minor version doesn’t change. (As before, your code will also work for newer versions of PyTek, as long as the major version number hasn’t changed).

The minor version number is changed only when something is added to the PyTek public interface, for instance a new function is added. Such a change maintains backward compatibility (as described above), but loses forward compatibility, because any client code written again this new version may not work with an older version.

The minor version number can be accessed through the MINOR member of this module.

Patch Version

The <patch> component is the patch number, and it describes changes that do not affect compatibility, either forwards or backwards. Your client code will continue to work with an older or newer version of PyTek as long as the major and minor version numbers are the same, regardless of the patch number.

Patch changes are code changes that do not effect the interface, for instance bug-fixes or performance enhancements. (although some bugs effect the interface and may therefore cause a higher version number to change).

The patch number can be accessed through the PATCH member of this module.

Semantic Version

The <semantic> component is the semantic version number, and it describes changes that do not affect how the code runs at all. Ths generally means that documentation or other auxilliary files included in the package have changed.

The semantic version number can be accessed through the SEMANTIC member of this module.

Compatibility Summary

The following table summarizes compatibility for a hypothetical client application built against released PyTek version M.n.p.s:

Component Compatibile (all) Incompatible (any)
Major M != M
minor >= n < n
patch any  
semantic any  
Version Tag

The <tag> component is the version tag, which is used only for non-released code. The tag has one of the following forms:

version tag ::=    << empty >>
                   dev[-<rev>]
                   blood-<branch>[-<rev>]

The first form is an empty tag, and is reserved for released (tagged) code only.

The second form, "dev", is for non-released code in the trunk. This is the main line of development. Dev code may not be completely functional, and may even break the existing interface.

The third form, "blood-...", if for non-released code on a branch. The <branch> component of this form should be the name of the branch. This is considered bleeding-edge code and may be highly unstable.

The optional <rev> component on both the second and third forms can be used to specify a specific revision for comitted development code. This must be an globally unambiguous identifier for the revision, for instance the change set id.

Development code

A non-empty version tag indicates a development version of the code. In this case, the four version numbers remain unchanged until the code is released (in which case it is no longer development code, and the tag is changed to empty).

In other words, anytime you see a non-empty version tag, the version numbers shown refer to version from which the development code is derived. This is done because it is not generally known until release what the next released version number will be, since it is not known what types of changes will be included in it.

Specifying a version number

When specifying a version number, the major and minor version numbers should always be included. Additionally, all non-zero version numbers should be included, and any version number to the left of a non-zero version number should be included.

The tag should always be included in the version number, with the indicated hyphen separating the semantic version number and the tag. The only exception is for released code, in which case the tag is empty and should be omitted, along with the joining hyphen.

The optional "x-" shown preceding the tag in the version number is for compatibility with setup-tools so that versions compare correctly.

The above rules will unambiguously describe any released version of the package.

Interface Version

Because any change to the public interface requires a change to either the major or minor version numbers, the interface can be specified by a shortened two part version:

interface version ::=    <Major>.<minor>

Note that this only applies for released versions: development versions may modify the public interface prior to changing the version numbers.

Release Number

The release number is a simple integer which increments by one for every public release of the code. It does not convey any information about compatibility with other versions, but it does provide a simple alternative to identifying released versions.

The release number should be written with a leading "r" or "rel". For instance, the first release was "r1".

For release code, the release number may be used in place of the tag in the version number. This is optional because the version number and the release number are synonymous. However, including them both in the version string is a useful way to provide both pieces of information.

This alternative form of the version number is:

alt. version number ::=    <Major>.<minor>[.<patch>[.<semantic>]]-r<release>

Module Contents

pytek.version.RELEASE = 2[bitbucket]

The current Release Number.

pytek.version.MAJOR = 1[bitbucket]

The current major version number.

pytek.version.MINOR = 1[bitbucket]

The current minor version number.

pytek.version.PATCH = 0[bitbucket]

The current patch version number.

pytek.version.SEMANTIC = 0[bitbucket]

The current semantic version number.

pytek.version.COPYRIGHT = 2014[bitbucket]

The copyright year for the PyTek code.

pytek.version.YEAR = 2014[bitbucket]

The year in which the code was released.

See also

pytek.version.MONTH = 4[bitbucket]

The month in which the code was released. This is 1 indexed, in [1, 12].

See also

pytek.version.DAY = 10[bitbucket]

The day of the month on which the code was released.

See also

pytek.version.TAG = None[bitbucket]

The current Version Tag.

Tag options are None, "dev", and "blood-"

  • None means this is a released/tagged version.
  • "dev" means this is a development version from the trunk/mainline.
  • "blood-" means it’s on a branch. After the dash, fill in the name of the branch.

Dev and blood versions are still numbered for the previous version, because we may not know what the next version will be until we’re finished.

pytek.version.MONTH_NAMES = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][bitbucket]

A sequence giving the names of months, for use by datestr. Standard values are three-letter English-language abbreviations for the months of the Gregorian calendar.

pytek.version.setuptools_string()[bitbucket][source]

Returns the version string used by setuptools. This takes one of two forms:

setuptools_string ::=    <Major>.<minor>.<patch>.<semantic>-x-<tag>
                         <Major>.<minor>.<patch>.<semantic>-r<release>

The first form is used for development code (i.e., when TAG is not None), and the second it used for released code.

This is similar to string, except for the additional x- for development versions, which is used to ensure that setuptools sorts versions correctly. (specifically, so that released versions are earler than development versions which are derived from them).

pytek.version.tag_name()[bitbucket][source]

Returns the tag name for the most recent release.

pytek.version.short_string()[bitbucket][source]

Returns a string describing the Interface Version (i.e., <Major>.<minor>).

pytek.version.string()[bitbucket][source]

Like setuptools_string, except leaves out the x- for development versions.

pytek.version.datestr()[bitbucket][source]

Returns a simple string giving the date of release. Format of this string is unspecified, it intended to be human readable, not machine parsed. For machine processing, use the individual variables, as listed below.

See also

LICENSE (GPLv3)

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  When you convey a copy of a covered work, you may at your option
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  Notwithstanding any other provision of this License, for material you
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  All other non-permissive additional terms are considered "further
restrictions" within the meaning of section 10.  If the Program as you
received it, or any part of it, contains a notice stating that it is
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  Additional terms, permissive or non-permissive, may be stated in the
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the above requirements apply either way.

  8. Termination.

  You may not propagate or modify a covered work except as expressly
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  However, if you cease all violation of this License, then your
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provisionally, unless and until the copyright holder explicitly and
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holder fails to notify you of the violation by some reasonable means
prior to 60 days after the cessation.

  Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
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your receipt of the notice.

  Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
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reinstated, you do not qualify to receive new licenses for the same
material under section 10.

  9. Acceptance Not Required for Having Copies.

  You are not required to accept this License in order to receive or
run a copy of the Program.  Ancillary propagation of a covered work
occurring solely as a consequence of using peer-to-peer transmission
to receive a copy likewise does not require acceptance.  However,
nothing other than this License grants you permission to propagate or
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  10. Automatic Licensing of Downstream Recipients.

  Each time you convey a covered work, the recipient automatically
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propagate that work, subject to this License.  You are not responsible
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  An "entity transaction" is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
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licenses to the work the party's predecessor in interest had or could
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the predecessor has it or can get it with reasonable efforts.

  You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License.  For example, you may
not impose a license fee, royalty, or other charge for exercise of
rights granted under this License, and you may not initiate litigation
(including a cross-claim or counterclaim in a lawsuit) alleging that
any patent claim is infringed by making, using, selling, offering for
sale, or importing the Program or any portion of it.

  11. Patents.

  A "contributor" is a copyright holder who authorizes use under this
License of the Program or a work on which the Program is based.  The
work thus licensed is called the contributor's "contributor version".

  A contributor's "essential patent claims" are all patent claims
owned or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner, permitted
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but do not include claims that would be infringed only as a
consequence of further modification of the contributor version.  For
purposes of this definition, "control" includes the right to grant
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this License.

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  In the following three paragraphs, a "patent license" is any express
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(such as an express permission to practice a patent or covenant not to
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party means to make such an agreement or commitment not to enforce a
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  If you convey a covered work, knowingly relying on a patent license,
and the Corresponding Source of the work is not available for anyone
to copy, free of charge and under the terms of this License, through a
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then you must either (1) cause the Corresponding Source to be so
available, or (2) arrange to deprive yourself of the benefit of the
patent license for this particular work, or (3) arrange, in a manner
consistent with the requirements of this License, to extend the patent
license to downstream recipients.  "Knowingly relying" means you have
actual knowledge that, but for the patent license, your conveying the
covered work in a country, or your recipient's use of the covered work
in a country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.

  If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
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receiving the covered work authorizing them to use, propagate, modify
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you grant is automatically extended to all recipients of the covered
work and works based on it.

  A patent license is "discriminatory" if it does not include within
the scope of its coverage, prohibits the exercise of, or is
conditioned on the non-exercise of one or more of the rights that are
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work if you are a party to an arrangement with a third party that is
in the business of distributing software, under which you make payment
to the third party based on the extent of your activity of conveying
the work, and under which the third party grants, to any of the
parties who would receive the covered work from you, a discriminatory
patent license (a) in connection with copies of the covered work
conveyed by you (or copies made from those copies), or (b) primarily
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contain the covered work, unless you entered into that arrangement,
or that patent license was granted, prior to 28 March 2007.

  Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.

  12. No Surrender of Others' Freedom.

  If conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License.  If you cannot convey a
covered work so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you may
not convey it at all.  For example, if you agree to terms that obligate you
to collect a royalty for further conveying from those to whom you convey
the Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.

  13. Use with the GNU Affero General Public License.

  Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU Affero General Public License into a single
combined work, and to convey the resulting work.  The terms of this
License will continue to apply to the part which is the covered work,
but the special requirements of the GNU Affero General Public License,
section 13, concerning interaction through a network will apply to the
combination as such.

  14. Revised Versions of this License.

  The Free Software Foundation may publish revised and/or new versions of
the GNU General Public License from time to time.  Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.

  Each version is given a distinguishing version number.  If the
Program specifies that a certain numbered version of the GNU General
Public License "or any later version" applies to it, you have the
option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation.  If the Program does not specify a version number of the
GNU General Public License, you may choose any version ever published
by the Free Software Foundation.

  If the Program specifies that a proxy can decide which future
versions of the GNU General Public License can be used, that proxy's
public statement of acceptance of a version permanently authorizes you
to choose that version for the Program.

  Later license versions may give you additional or different
permissions.  However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

  15. Disclaimer of Warranty.

  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

  16. Limitation of Liability.

  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.

  17. Interpretation of Sections 15 and 16.

  If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<http://www.gnu.org/licenses/>.

  The GNU General Public License does not permit incorporating your program
into proprietary programs.  If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

Indices and tables

Version

This documentation is for PyTek 1.1 (v1.1.0.0-r2).