Repository navigation
Compatibility issue between argparse and pythonnet packages #404
Description
Environment
- Pythonnet version: 2.3.0.dev1 (built from master on 23/02/2017)
- Python version: 2.7.13 64bit
- Operating System: Windows 7 64bit
Details
- I tested the pythonnet version from yesterday, 23/02/2017, as we are interested in the bug fix for the method overload issue Method overload object type #377. I noticed that we are now running into compatibility issues with the package argparse.
The package argparse now only works correctly, if the parsing of the command line arguments is done BEFORE the import statement of pythonnet (import clr).
If I revert my pythonnet version to pythonnet==2.2.2, then the problem disappears.
The following minimal test code illustrates the problem:
file: test.py
import argparse
# import clr # can't put it here, args.arg1 will be None
parser = argparse.ArgumentParser()
parser.add_argument('--arg1', '-a', help='argument 1', dest='arg1')
args = parser.parse_args()
import clr
print('Argument 1 = ')
print(args.arg1)
Then I start the script from command line as
python test.py --arg1 "Hello World"
If I run the code with the "import clr" statement after the call to parser.parse_args() then I get the desired output:
Argument 1 =
hello world
However, if I put the "import clr" at the beginning of the file, I get the output:
Argument 1 =
None
Activity
den-run-ai commentedon Feb 24, 2017
can you try before this pull request?
#347
den-run-ai commentedon Feb 24, 2017
@filmor can you have a look at this, since this is most likely your pull request.
@vmuriart looks like you imported clr before setargv tests, hence this case was not tested:
#301
vmuriart commentedon Feb 24, 2017
@sg08013 can you verify that
sys.argvis returning asNonein the 2nd case.@denfromufa yup. Though looking at the issue, it would have been better to test
sys.argv is not Noneand then when it's imported shouldn't matter.den-run-ai commentedon Feb 24, 2017
no, we need to check that sys.argv is not modified. Checking against None is not enough. Generally
is not Noneis better syntax.filmor commentedon Feb 24, 2017
It should suffice to pass the information to
Initializethat we are currently running in "module-mode" and skip the setting of argv in that case. I'll prepare a PR.den-run-ai commentedon Feb 24, 2017
hey, guys, sorry if I sounded rude. i'm actually rude by design :)
sg08013 commentedon Feb 24, 2017
I just tested the value of sys.argv with the following code:
vmuriart commentedon Feb 24, 2017
I can't think of a good way to write the test for this without breaking how
pytestis designed to work. The best i can come up w is to have the test execute an external script viasubprocessand report the result from it.vmuriart commentedon Feb 24, 2017
I would also like to point out that this is issue
404 - sys.args not found.den-run-ai commentedon Feb 24, 2017
@vmuriart you can check if sys has args with hasattr. sys.args does not exist yet after Py_Initialize() in embedded mode.
@sg08013 thanks for reporting the issue!
Fix the issue of sys.argv being cleared on import clr.
vmuriart commentedon Feb 24, 2017
Fixed the test on 012b488 to reflect the behavior being seen. Its marked as
xfailfor now until we fix it.Here's the test running against v2.2.2 showing that it worked.
https://travis-ci.org/vmuriart/pythonnet/jobs/204904097
Thanks @sg08013 for reporting and providing the example.
side note, @sg08013 were you able to test if #377 fixed your other issue?
sg08013 commentedon Feb 24, 2017
@vmuriart I can't say yet, whether our issue is entirely resolved. We were having problems using overloaded methods from a C# assembly (in python). There were no crashes or exceptions, just empty return values. This part now runs through (=is resolved), but there is still something that does not work as expected (but this might be unrelated).
I will let you know when I understand it better.
sg08013 commentedon Feb 24, 2017
And thanks to all of you for taking care of this issue so quickly! That's highly appreciated.
Fix the issue of sys.argv being cleared on import clr.
Fix the issue of sys.argv being cleared on import clr.
Fix the issue of sys.argv being cleared on import clr.
Fix the issue of sys.argv being cleared on import clr.
Rebase with master (#2)