Adding Python 3 compatibility

[mlouielu]

Is your feature request related to a problem? Please describe.
In Python 3 default environment, using cFS-GroundSystem is a little tricky, since GroundSystem.py will use /usr/bin/env python for the Subsystem.

And the PyQt4 needs compile & build, it is hard to deploy in the virtual environment for it.

Describe the solution you'd like
Adding Python 3 compatibility for cFS-GroundSystem code.

Describe alternatives you've considered
By using 2to3, we can convert most of the code.

Only 2 parts need to concern:

• csv reader open file
  • Adding a middle layer of open, or detect version in each files
• zmq.socket.setsockopt
  • Does the subscription name need to support utf-8?

Additional context
No

Requester Info
Louie Lu / Advanced Rocket Research Center, NCTU, Taiwan

[mlouielu]

Or, does NASA accept/migrate to Python 3 only code? I'm not sure if this is acceptable or not.

[skliper]

Good issue, we do plan to update but as of today I can't except external contributions yet (still trying to get the process in place). Hopefully soon!

@dmknutsen

[mlouielu]

Reading csv file should use open(filename, 'r', newline='') in Python 3.

Otherwise it will raise up:

>>> with open('cs-hk-tlm.txt', 'rb') as f:
...  reader = csv.reader(f)
...  for r in reader:
...   print(r)
... 
Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
_csv.Error: iterator should return strings, not bytes (did you open the file in text mode?)

This didn't address in de8c151.