Add new SYSTEC interface with docu

[idaniel86]

No description provided.

[hardbyte]

Thanks for the PR! As a heads up it can take a while to get newly contributed interfaces reviewed and merged in - although after a brief look this looks great. Not often docs come from the start!

Any how I'll try spend a few hours this weekend or next but if anyone else wants to do a code review please jump in.

[idaniel86]

I have checked the failed checks. The issue is that the driver library was not installed as described in the documentation. My question is, should there be an ImportError thrown when configuration detection is executed and the library was not found? Or an empy configuration should be returned? Or?

[hardbyte]

Overall this looks good to merge once the C.I system approves.

[hardbyte]

There is an encoding error here.

ucanbus.py                  35 WARNING  Cannot load SYSTEC ucan library: Non-ASCII character '\xe2' in file C:\projects\python-can\can\interfaces\systec\ucan.py on line 350, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details (ucan.py, line 349)

[hardbyte]

This static method has to work even if Ucan isn't defined

[hardbyte]

Personally I like the approach in serial.py:

try:
    import serial
except ImportError:
    logger.warning("You won't be able to use the serial can backend without "
                   "the serial module installed!")
    serial = None

[codecov]

Codecov Report

Merging #466 into develop will increase coverage by 0.58%.
The diff coverage is 67.26%.

@@             Coverage Diff             @@
##           develop     #466      +/-   ##
===========================================
+ Coverage    63.29%   63.88%   +0.58%     
===========================================
  Files           57       63       +6     
  Lines         4784     5615     +831     
===========================================
+ Hits          3028     3587     +559     
- Misses        1756     2028     +272

[idaniel86]

Hi, what is the "Codecov Report"? It has something to do with unittesting?

[hardbyte]

Yeah codecov measures how much code was executed by the ci system (travis-ci). For this PR travis ran these unit tests and pushed the code coverage to https://codecov.io/gh/hardbyte/python-can/pull/466/diff

In this case as the interface has no unittests it just shows the lines with definitions as green - i.e. what lines were imported before the except Exception as ex in ucanbus.py was triggered.

It isn't a required check before merging, just applies a gentle pressure to encourage tested code! We ensure the core of python-can is well tested, but as the interfaces are all individual contributions they are tested at different levels.

If you're willing it certainly would be better to add a few tests that don't require hardware (or the usbcan.dll). The Kvaser interface does this with mocking.

[idaniel86]

I have tried to add tests for the interface. The interface is only for Windows platform, it fails on the CI, cause the structures use wintypes and some of them also WINFUNCTYPEs which do not exist under Linux. Any ideas how to fix this?

[idaniel86]

Ok, I have added a workaround to allow the Unix based testing system use the interface for testing purposes.

[hardbyte]

Thanks for the contribution!