Spacing around colons can crash pycodestyle_magic

[cmichal2]

Using pycodestyle in "cell-at-a-time" mode, with %%pycodestyle as the first line in a cell seems to be very sensitive the spacing around colons.

In particular, a space before a colon that introduces a new block, such as: for i in range(5) : will crash it with an error that appears to be related to parsing windows drive names, though I'm using this on linux. Similar errors occur in defining a dictionary if there is a space before a colon or no space after a colon.

 ---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-4-ec9d1225e653> in <module>()
----> 1 get_ipython().run_cell_magic('pycodestyle', '', 'for i in range(4) :\n    pass')

/usr/lib64/python3.6/site-packages/IPython/core/interactiveshell.py in run_cell_magic(self, magic_name, line, cell)
   2115             magic_arg_s = self.var_expand(line, stack_depth)
   2116             with self.builtin_trap:
-> 2117                 result = fn(magic_arg_s, cell)
   2118             return result
   2119 

/home/p210nb/.local/lib64/python3.6/site-packages/pycodestyle_magic.py in pycodestyle(line, cell, auto)
    173         #logger.info(line)
    174         # on windows drive path also contains :
--> 175         line, col, error = line.split(':')[-4:]
    176         # do not subtract 1 for line for %%pycodestyle, inc pre py3.6 string
    177         if auto:

ValueError: too many values to unpack (expected 3)

[mattijn]

Thanks for raising the issue! If I try to emulate the error you got I got no hard errors, but mainly styling errors as such:

Could you provide more information on the version of ipython \ pycodestyle_magic etc. Maybe we can find some discrepancy there?

[mattijn]

Oh wait. I didn't read your issue right.. I can reproduce the error. Hm, indeed strange!

[mattijn]

This line:

line, col, error = line.split(':')[-4:] 

splits on :, which goes wrong when there is an : in the error. I can replace it with the following

line_split = line.split(' ')
line, col, _ = line_split[0].split(':')[-3:]
error = ' '.join(line_split[1::]) 

But I broke my python print() function doing so.. It seems. But for now, it doesn't print anything anymore. Will check soon on a windows machine if there is this behaviour also occurs..