How do I preserve underscores in arguments?

[MattKleinsmith]

Here's run.py:

import fire

def f(x):
    print(x)

if __name__ == '__main__':
    fire.Fire(f)

Command: python run.py --x 20180217_064501

Output:

20180217064501

Expected output:

20180217_064501

[MattKleinsmith]

These issues seem related: https://github.com/google/python-fire/issues/102 https://github.com/google/python-fire/issues/97

[dbieber]

I'm not able to reproduce this issue. When I run python run.py --x 20180217_064501 I get the expected output 20180217_064501.

What version of Python are you using? What version of fire?

[MattKleinsmith]

Python 3.6.3 fire 0.1.2, installed via pip OS: Ubuntu 16.04 on Docker and host

I should have included this information in the original post. My apologies.

[MattKleinsmith]

With this Dockerfile I get the expected output:

FROM ubuntu:16.04

RUN apt-get update --fix-missing && apt-get install -y \
    python3 \
    python3-pip \
    vim \
    wget

RUN pip3 install fire

RUN wget https://raw.githubusercontent.com/MattKleinsmith/dockerfiles/master/errors/fire/run.py

CMD ["python3", "run.py", "--x", "20180217_064501"]

[MattKleinsmith]

When I install Anaconda and use its provided pip to install fire, I get the erroneous output.

Here's a Dockerfile reproducing the issue.

[frextrite]

Tested with anaconda and python 2.7.15, I was getting the expected output. Then tested with anaconda and python 3.5.3(latest version available on Ubuntu 16.04, dockerfile uses 3.5.2) and again got the expected output. Then tested with anaconda and python 3.6.5 and got the erroneous output. Maybe the problem is with python 3.6+

[JadeIden]

It looks like an issue with PEP 515 and underscores in numbers, which was implemented in Python 3.6. It seems like underscores between numbers are more likely to be used as part of a string rather than for a long number, so it could be worthwhile to, when we encounter a number with an underscore in it during traversal, treat it as a string instead.

I can take a shot at implementing that if that is the chosen solution.

[kyle-goodwin]

@JadeIden Do you still feel like implementing something? I tracked down where this happens but implementing a fix for this is well beyond me.

This is caused by line 96 of parser.py in the _LiteralEval function. Specifically root = ast.parse(value, mode='eval').

This can be demonstrated with the following code:

import ast
root = ast.parse("123_456", mode='eval')
print(root.body.value)

prints 123456.

[farridav]

*bump, this is also affecting me, any news on a workaround ? why not inspect the type annotations (if present) and use that to bias the type ?

[dbieber]

One (poor :() workaround for the moment is to surround your argument with quotes... twice...

python run.py --x '"20180217_064501"'

The outer quotes get stripped by your shell, leaving just the inner quotes to be parsed by Python Fire, resulting in the arg getting treated as a string rather than a number.