Question

Sorry if the question is bit confusing. This is similar to this question

I think this the above question is close to what I want, but in Clojure.

There is another question

I need something like this but instead of ‘[br]’ in that question, there is a list of strings that need to be searched and removed.

Hope I made myself clear.

I think that this is due to the fact that strings in python are immutable.

I have a list of noise words that need to be removed from a list of strings.

If I use the list comprehension, I end up searching the same string again and again. So, only “of” gets removed and not “the”. So my modified list looks like this

places = ['New York', 'the New York City', 'at Moscow' and many more]

noise_words_list = ['of', 'the', 'in', 'for', 'at']

for place in places:
    stuff = [place.replace(w, "").strip() for w in noise_words_list if place.startswith(w)]

I would like to know as to what mistake I’m doing.

Answer 1

Here is my stab at it. This uses regular expressions.

import re
pattern = re.compile("(of|the|in|for|at)\W", re.I)
phrases = ['of New York', 'of the New York']
map(lambda phrase: pattern.sub("", phrase),  phrases) # ['New York', 'New York']

Sans lambda:

[pattern.sub("", phrase) for phrase in phrases]

Update

Fix for the bug pointed out by gnibbler (thanks!):

pattern = re.compile("\\b(of|the|in|for|at)\\W", re.I)
phrases = ['of New York', 'of the New York', 'Spain has rain']
[pattern.sub("", phrase) for phrase in phrases] # ['New York', 'New York', 'Spain has rain']

@prabhu: the above change avoids snipping off the trailing “in” from “Spain”. To verify run both versions of the regular expressions against the phrase “Spain has rain”.