chaining regular expressing in python

Question

Hello I'm currently trying to parse a script that contains paths to files similar to the ones given below. I would like to parse the file using regular expressions and store the data into a string with '\\n' separation between files. Example file given below.

    SAMPLE FILE: ('#' is a comment would like to keep commented out)
    add file -tls "../path1/path2/path3/example_1.edf"
    add file -tls "../path1/path2/path3/example_1.v"
    add file -tls "../path1/path2/path3/exa_4mple_1.sv"
    add file -tls "../path1/path2/path3/example_1.vh"        
    #add file -tls "../path1/path2/path3/exa_0mple_1.vhd"

    SAMPLE OUTPUT: (this example excludes the '\n' character)
    example_1.v
    exa_4mple_1.sv
    example_1.vh
    #exa_0mple_1.vhd

How can I construct the extension 're' so that it only includes the above extensions and excludes others? I'm also wondering if it's possible to catch the '#' for commented out lines and prepend it the file name with a '#'.

    -Desired function:
    for match in re.finditer(r'/([A-Za-z0-9_]+\..+)"', contents):
       mylist.append(match.group(1))

    -Working Code: ( tested on the '.v' file case )
    re.finditer(r'/([A-Za-z0-9_]+\.v)"', contents)

Answer 1

Regular expressions are not needed:

>>> import os
>>> L = [
... "/path1/path2/path3/example_1.edf", 
... "/path1/path2/path3/example_1.v",
... "/path1/path2/path3/exa_4mple_1.sv", 
... "/path1/path2/path3/example_1.vh" ]
>>> for mypath in L:
...     if mypath.split('.')[-1] in ('v', 'sv', 'vh'):
...             print os.path.split(mypath)[1]
... 
example_1.v
exa_4mple_1.sv
example_1.vh

Or as a list comprehension:

>>> [os.path.split(mypath)[1] 
... for mypath in L 
... if mypath.split('.')[-1] in ('v', 'sv', 'vh')]
['example_1.v', 'exa_4mple_1.sv', 'example_1.vh']

Answer 2

Is this what you want ? :

import re

contents = '''
add file -tls "../path1/path2/path3/example_1.edf"
add file -tls "../path1/path2/path3/example_1.v"
add file -tls "../path1/path2/path3/exa_4mple_1.sv"     
add file -tls "../path1/path2/path3/example_1.vh"     
#add file -tls "../path1/path2/path3/exa_0mple_1.vhd"
'''

print contents

pat = "^(#?)add file.+?\"\.\./(?:\w+/)*(\w+?\.\w*v\w*)\"\s*$"

gen = (''.join(mat.groups())
       for mat in re.finditer(pat,contents,re.MULTILINE))

print '\n'.join(gen)

The pattern allows to catch paths with extensions containing the letter 'v', that's waht I understood from your question.
I also put the string add file as a criterium of catching, according to your example.
I used \\w in the pattern.
With this pattern, all paths are supposed to begin with ../
If all these characteristcs aren't adapted to your case, we'll change what needs to be changed.

Note that I put \\s* at the end of the pattern, in case there are whitespaces in the line after the path.