Efficiently Strip Out Punctuation but not ".com"

Question

I found this thread: Best way to strip punctuation from a string in Python

But was hoping to come up with a way to do this except not to strip out the periods in links. So if the string is

I love using stackoverflow.com on Fridays, Saturdays and Mondays!

It would return

I love using stackoverflow.com on Fridays Saturdays and Monday

In fact ideally I would be able to pass in a list of common link endings like .com, .net, .ly etc.

How about just stripping punctuation before a white space character? Or is this not "good enough"? — Felix Kling, Mar 18 '11 at 16:23
Hmmm thought of that, but that wouldn't remove the exclamation point in the above example. — JiminyCricket, Mar 18 '11 at 16:26
I think Felix's solution is the way to go here. You're forgetting all sorts of valid domains like programmers.stackexchange.com, for example. Although, I'm wondering why someone would want to strip the punctuation in the first place. — Karl Bielefeldt, Mar 18 '11 at 16:29
You can consider the end of the string to also be "whitespace." — Karl Bielefeldt, Mar 18 '11 at 16:30

score 5 · Accepted Answer · answered Mar 18 '11 at 16:27

5

You can use negative look-aheads:

[,!?]|\.(?!(com|org|ly))

answered Mar 18 '11 at 16:27

Jacob

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score 3 · Answer 2 · answered Mar 18 '11 at 16:26

Conventions suggest that you use a space after . , ! or things like that. If you can count on correct typing you can create a regex which strips these character only if they are followed by spaces. (Or at least do like this with the fullstop character).

The following regex will identify these:

[.,!?-](\s|$)

An other possibility is to use a list of legal TLD names. prefixes like www. or other patters like @ which keep the original punctuation around them.

score 1 · Answer 3 · edited Mar 18 '11 at 17:33

1

how about this (which is pretty much what Felix Kling already suggested):

original = 'I love using stackoverflow.com on Fridays, Saturdays and Mondays!'
unwanted_chars = ',.!?;:'

bits = original.split()
cleaned_up = ' '.join([bit.strip(unwanted_chars) for bit in bits])
print cleaned_up
# I love using stackoverflow.com on Fridays Saturdays and Mondays

edit:

ps: 'cleaned_up' would then be the depunctuated string

edited Mar 18 '11 at 17:33

martineau

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answered Mar 18 '11 at 16:39

HumanCatfood

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+1: Could be one liner: `cleaned_up = ' '.join([bit.strip(',.!?;:') for bit in original.split()])` – martineau Mar 18 '11 at 17:37

Efficiently Strip Out Punctuation but not ".com"

3 Answers3