Python: binary string error simulation - python

I am currently writing a test for validating some error-correcting code:
inputData1 = "1001011011"
inputData2 = "1001111011"
fingerPrint1 = parityCheck.getParityFingerprint(inputData1)
# Expected: fingerPrint1=0
fingerPrint2 = parityCheck.getParityFingerprint(inputData2)
# Expected: fingerPrint2=1
if fingerPrint1 == fingerPrint2:
print "Test failed: errorCorrectingAlgo1 failed to detect error"
else:
print "Test success: errorCorrectingAlgo1 successfully detected error"
Is there a python class I can use to automatically generate error(burst error, single event, reordering, etc) on a binary string? Eg:
inputData1 = "1001011011"
inputData1BurstError = applyBurstError(inputData1) # Eg: inputData1BurstError =
("1011111011", or "1001000000", or etc.)
inputData1RandomError = applyRandomError(inputData1)# Eg: inputData1RandomError =
("0001101011", or "0111101101", or etc.)
inputData1Reordering = applyReordering(inputData1) # Eg: inputData1Reordering =
("0101110011", or "1101101001", or etc.)
inputData1SingleEvent = applySingleEvent(inputData1)# Eg: inputData1SingleEvent =
("1001011011", or "1000011011", or etc.)
I know that such a class could be easily implementable for binary check validation. However, I need a more complete class to test more complex error detecting code such as CRC. I have already used Netem (http://www.linuxfoundation.org/collaborate/workgroups/networking/netem) in the past to modify packets entering and leaving interfaces in a telecom lab. However, I doubt Netem would be a good solution to my problem this time as my whole test is planned to be run on my desktop computer only. Also, I am working on Windows 7 this time. Moreover, Netem does not provide a complete/complex enough set of functions for my test implementation.
Any help/suggestion would be greatly appreciated.
Thanks!
Related question: How to shuffle a list with Gaussian distribution

Related

CANoe: How to select and start test cases from XML Test Module from Python using CANoe COM interface?

currently I am able to:
start CANoe application
load a CANoe configuration file
load a test setup file
def load_test_setup(self, canoe_test_setup_file: str = None) -> None:
logger.info(
f'Loading CANoe test setup file <{canoe_test_setup_file}>.')
if self.measurement.Running:
logger.info(
f'Simulation is currently running, so new test setup could \
not be loaded!')
return
self.test_setup.TestEnvironments.Add(canoe_test_setup_file)
test_environment = self.test_setup.TestEnvironments.Item(1)
logger.info(f'Loaded test environment is <{test_environment.Name}>.')
How can I access the XML Test Module loaded with the test setup (tse) file and select tests to be executed?
The last before line in your snippet is most probably causing the issue.
I have been trying to fix this issue for quite some time now and finally found the solution.
Somehow when you execute the line self.test_setup.TestEnvironments.Item(1)
win32com creates an object of type TestSetupItem which doesn't have the necessary properties or methods to access the test cases. Instead we want to access objects of collection types TestSetupFolders or TestModules. win32com creates object of TestSetupItem type even though I have a single XML Test Module (called AutomationTestSeq) in the Test Environment as you can see here.
There are three possible solutions that I found.
Manually clearing the generated cache before each run.
Using win32com.client.DispatchWithEvents or win32com.client.gencache.EnsureDispatch generates a bunch of python files that describe CANoe's object model.
If you had used either of those before, TestEnvironments.Item(1) will always return TestSetupItem instead of the more appropriate type objects.
To remove the cache you need to delete the C:\Users\{username}\AppData\Local\Temp\gen_py\{python version} folder.
Doing this every time is of course not very practical.
Force win32com to always use dynamic dispatch.
You can do this by using:
canoe = win32com.client.dynamic.Dispatch("CANoe.Application")
Any objects you create using canoe from now on, will be dynamically dispatched.
Forcing dynamic dispatch is easier than manually clearing the cache folder every time. This gave me good results always. But doing this will not let you have any insight into the objects. You won't be able to see the acceptable properties and methods for the objects.
Typecast TestSetupItem to TestSetupFolders or TestModules.
This has the risk that if you typecast incorrectly, you will get unexpected results. But has worked well for me so far.
In short: win32.CastTo(test_env, "ITestEnvironment2"). This will ensure that you are using the recommended object hierarchy as per CANoe technical reference.
Note that you will also have to typecast TestSequenceItem to TestCase to be able to access test case verdict and enable/disable test cases.
Below is a decent example script.
"""Execute XML Test Cases without a pass verdict"""
import sys
from time import sleep
import win32com.client as win32
CANoe = win32.DispatchWithEvents("CANoe.Application")
CANoe.Open("canoe.cfg")
test_env = CANoe.Configuration.TestSetup.TestEnvironments.Item('Test Environment')
# Cast required since test_env is originally of type <ITestEnvironment>
test_env = win32.CastTo(test_env, "ITestEnvironment2")
# Get the XML TestModule (type <TSTestModule>) in the test setup
test_module = test_env.TestModules.Item('AutomationTestSeq')
# {.Sequence} property returns a collection of <TestCases> or <TestGroup>
# or <TestSequenceItem> which is more generic
seq = test_module.Sequence
for i in range(1, seq.Count+1):
# Cast from <ITestSequenceItem> to <ITestCase> to access {.Verdict}
# and the {.Enabled} property
tc = win32.CastTo(seq.Item(i), "ITestCase")
if tc.Verdict != 1: # Verdict 1 is pass
tc.Enabled = True
print(f"Enabling Test Case {tc.Ident} with verdict {tc.Verdict}")
else:
tc.Enabled = False
print(f"Disabling Test Case {tc.Ident} since it has already passed")
CANoe.Measurement.Start()
sleep(5) # Sleep because measurement start is not instantaneous
test_module.Start()
sleep(1)
Just continue what you have done.
The TestEnvironment contains the TestModules. Each TestModule contains a TestSequence which in turn contains the TestCases.
Keep in mind that you cannot individual TestCases but only the TestModule. But you can enable and disable individual TestCases before execution by using the COM-API.
(typing this from the top of my head, might not work 100%)
test_module = test_environment.TestModules.Item(1) # of 2 or whatever
test_sequence = test_module.Sequence
for i in range(1, test_sequence.Count + 1):
test_case = test_sequence.Item(i)
if ...:
test_case.Enabled = False # or True
test_module.Start()
You have to keep in mind that a TestSequence can also contain other TestSequences (i.e. a TestGroup). This depends on how your TestModule is setup. If so, you have to take care of that in your loop and descend into these TestGroups while searching for your TestCase of interest.

How to link interactive problems (w.r.t. CodeJam)?

I'm not sure if it's allowed to seek for help(if not, I don't mind not getting an answer until the competition period is over).
I was solving the Interactive Problem (Dat Bae) on CodeJam. On my local files, I can run the judge (testing_tool.py) and my program (<name>.py) separately and copy paste the I/O manually. However, I assume I need to find a way to make it automatically.
Edit: To make it clear, I want every output of x file to be input in y file and vice versa.
Some details:
I've used sys.stdout.write / sys.stdin.readline instead of print / input throughout my program
I tried running interactive_runner.py, but I don't seem to figure out how to use it.
I tried running it on their server, my program in first tab, the judge file in second. It's always throwing TLE error.
I don't seem to find any tutorial to do the same either, any help will be appreciated! :/
The usage is documented in comments inside the scripts:
interactive_runner.py
# Run this as:
# python interactive_runner.py <cmd_line_judge> -- <cmd_line_solution>
#
# For example:
# python interactive_runner.py python judge.py 0 -- ./my_binary
#
# This will run the first test set of a python judge called "judge.py" that
# receives the test set number (starting from 0) via command line parameter
# with a solution compiled into a binary called "my_binary".
testing_tool.py
# Usage: `testing_tool.py test_number`, where the argument test_number
# is 0 for Test Set 1 or 1 for Test Set 2.
So use them like this:
python interactive_runner.py python testing_tool.py 0 -- ./dat_bae.py

How to assign a 2d libreoffice calc named range to a python variable. Can do it in Libreoffice Basic

I can't seem to find a simple answer to the question. I have this successfully working in Libreoffice Basic:
NamedRange = ThisComponent.NamedRanges.getByName("transactions_detail")
RefCells = NamedRange.getReferredCells()
Set MainRange = RefCells.getDataArray()
Then I iterate over MainRange and pull out the rows I am interested in.
Can I do something similar in a python macro? Can I assign a 2d named range to a python variable or do I have to iterate over the range to assign the individual cells?
I am new to python but hope to convert my iteration intensive macro function to python in hopes of making it faster.
Any help would be much appreciated.
Thanks.
LibreOffice can be manipulated from Python with the library pyuno. The documentation of pyuno is unfortunately incomplete but going through this tutorial may help.
To get started:
Python-Uno, the library to communicate via Uno, is already in the LibreOffice Python’s path. To initialize your context, type the following lines in your python shell :
import socket # only needed on win32-OOo3.0.0
import uno
# get the uno component context from the PyUNO runtime
localContext = uno.getComponentContext()
# create the UnoUrlResolver
resolver = localContext.ServiceManager.createInstanceWithContext(
"com.sun.star.bridge.UnoUrlResolver", localContext )
# connect to the running office
ctx = resolver.resolve( "uno:socket,host=localhost,port=2002;urp;StarOffice.ComponentContext" )
smgr = ctx.ServiceManager
# get the central desktop object
desktop = smgr.createInstanceWithContext( "com.sun.star.frame.Desktop",ctx)
# access the current writer document
model = desktop.getCurrentComponent()
Then to get a named range and access the data as an array, you can use the following methods:
NamedRange = model.NamedRanges.getByName(“Test Name”)
MainRange = NamedRange.getDataArray()
However I am unsure that this will result in a noticeable preformance gain.

What is the simplest way to get from MIDI to real audio coming out my speakers (sound synthesis) in Python?

I'm starting work on an app that will need to create sound from lots of pre-loaded ".mid" files.
I'm using Python and Kivy to create an app, as I have made an app already with these tools and they are the only code I know. The other app I made uses no sound whatsoever.
Naturally, I want to make sure that the code I write will work cross-platform.
Right now, I'm simply trying to prove that I can create any real sound from a midi note.
I took this code suggested from another answer to a similar question using FluidSynth and Mingus:
from mingus.midi import fluidsynth
fluidsynth.init('/usr/share/sounds/sf2/FluidR3_GM.sf2',"alsa")
fluidsynth.play_Note(64,0,100)
But I hear nothing and get this error:
fluidsynth: warning: Failed to pin the sample data to RAM; swapping is possible.
Why do I get this error, how do I fix it, and is this the simplest way or even right way?
I could be wrong but I don't think there is a "0" channel which is what you are passing as your second argument to .play_Note(). Try this:
fluidsynth.play_Note(64,1,100)
or (from some documentation)
from mingus.containers.note import Note
n = Note("C", 4)
n.channel = 1
n.velocity = 50
fluidSynth.play_Note(n)
UPDATE:
There are references to only channels 1-16 in the source code for that method with the default channel set to 1:
def play_Note(self, note, channel = 1, velocity = 100):
"""Plays a Note object on a channel[1-16] with a \
velocity[0-127]. You can either specify the velocity and channel \
here as arguments or you can set the Note.velocity and Note.channel \
attributes, which will take presedence over the function arguments."""
if hasattr(note, 'velocity'):
velocity = note.velocity
if hasattr(note, 'channel'):
channel = note.channel
self.fs.noteon(int(channel), int(note) + 12, int(velocity))
return True

Making all attributes and methods available for a socket server in Python

I use a Raspberry Pi to collect sensor data and set digital outputs, to make it easy for other applications to set and get values I'm using a socket server. But I am having some problems finding an elegant way of making all the data available on the socket server without having to write a function for each data type.
Some examples of values and methods I have that I would like to make available on the socket server:
do[2].set_low() # set digital output 2 low
do[2].value=0 # set digital output 2 low
do[2].toggle() # toggle digital output 2
di[0].value # read value for digital input 0
ai[0].value # read value for analog input 0
ai[0].average # get the average calculated value for analog input 0
ao[4].value=255 # set analog output 4 to byte value 255
ao[4].percent=100 # set analog output 4 to 100%
I've tried eval() and exec():
self.request.sendall(str.encode(str(eval('item.' + recv_string)) + '\n'))
eval() works unless I am using equal sign (=), but I'm not to happy about the solution because of dangers involved. exec() does the work but does not return any value, also dangerous.
I've also tried getattr():
recv_string = bytes.decode(self.data).lower().split(';')
values = getattr(item, recv_string[0])
self.request.sendall(str.encode(str(values[int(recv_string[1])].value) + '\n'))
^^^^^
This works for getting my attributes, and the above example works for getting the value of the attribute I am getting with getattr(). But I can not figure out how to use getattr() on the value attribute as well.
The semi-colon (;) is used to split the incoming command, I've experimented with multiple ways of formatting the commands:
# unit means that I want to talk to a I/O interface module,
# and the name specified which one
unit;unit_name;get;do;1
unit;unit_name;get;do[1]
unit;unit_name;do[1].value
I am free to choose the format since I am also writing the software that uses these commands. I have not yet found a good format which covers all my needs.
Any suggestions how I can write an elegant way of accessing and returning the data above? Preferably with having to add new methods to the socket server every time a new value type or method is added to my I/O ports.
Edit: This is not public, it's only available on my LAN.
Suggestions
Make your API all methods so that eval can always be used:
def value_m(self, newValue=None):
if newValue is not None:
self.value = newValue
return self.value
Then you can always do
result = str(eval(message))
self.request.sendall(str.encode(result + '\n'))
For your message, I would suggest that your messages are formatted to include the exact syntax of the command exactly so that it can be evaled as-is, e.g.
message = 'do[1].value_m()' # read a value, alternatively...
message = 'do[1].value_m(None)'
or to write
message = 'do[1].value_m(0)' # write a value
This will make it easy to keep your messages up-to-date with your API, because they must match exactly, you won't have a second DSL to deal with. You really don't want to have to maintain a second API, on top of your IO one.
This is a very simple scheme, suitable for a home project. I would suggest some error handling in evaluation, like so:
import traceback
try:
result = str(eval(message))
except Exception:
result = traceback.format_exc()
self.request.sendall(str.encode(result + '\n'))
This way your caller will receive a printout of the exception traceback in the returned message. This will make it much, much easier to debug bad calls.
NOTE If this is public-facing, you cannot do this. All input must be sanitised. You will have to parse each instruction and compare it to the list of available (and desirable) commands, and verify input validity and validity ranges for everything. For such a scenario you are better off simply using one of the input validation systems used for web services, where this problem receives a great deal of attention.

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