Splitting a string by spaces without space-splitting elements in double-quotes

Question

I need to split a command like:

r' "C:\Program Files (x86)\myeditor" "$FILEPATH" -n$LINENO "c:\Program Files" -f$FILENAME -aArg2'`

into:

['"C:\\Program Files (x86)\\myeditor"',
 '"$FILEPATH"',
 '-n$LINENO',
 '"c:\\Program Files"',
 '-f$FILENAME',
 '-aArg2']

That is, I want to split by spaces, but avoid splitting the elements in double-quotes.

I have this code:

import re
s = r' "C:\Program Files (x86)\myeditor" "$FILEPATH" -n$LINENO "c:\Program Files" -f$FILENAME -aArg2'
start = end = 0
split = []
for elem in re.findall('".*?"', s):
 end = s.find(elem)
 split.append(s[start:end])
 split.append(elem)
 start = end + len(elem)
split.extend(s[start:].split())
split = [elem.strip() for elem in split]
split = list(filter(None, split))

It works, but I'm wondering if there's some more elegant/shorter/more readable way to do that in Python(3) ?

• tar: Already answered: stackoverflow.com/q/366202/823470
• LetMeSOThat4U: @tar That answer is on Java and some complex regexes. I think that shlex + copying doublequotes is a more pythonic and sensible approach, as it follows line of thinking "use the standard library if it does the job".

Answer 1

The best way to do what you want with the standard library would be shlex.split():

>>> import shlex
>>> s = r' "C:\Program Files (x86)\myeditor" "$FILEPATH" -n$LINENO "c:\Program Files" -f$FILENAME -aArg2'
>>> shlex.split(s)
['C:\\Program Files (x86)\\myeditor', '$FILEPATH', '-n$LINENO', 'c:\\Program Files', '-f$FILENAME', '-aArg2']

Note that the quotes are not retained.

Answer 2

You could use a different regex:

import re
s = r' "C:\Program Files (x86)\myeditor" "$FILEPATH" -n$LINENO "c:\Program Files" -f$FILENAME -aArg2'
pattern = re.compile(r"((\"[^\"]+\")|(-[^\s]+))")
for m in re.finditer(pattern, s):
 print(m.group(0))

This regex will match either an item enclosed by double quotes (") or an item prepended with a dash (-).

However this might be harder to read/grasp and I'm also not sure if this is considered pythonic as it's the Perl way of doing things so take this with a grain of salt.