Question

I have a list of strings in which I want to filter for strings that contains keywords.

I want to do something like:

fruit = re.compile('apple', 'banana', 'peach', 'plum', 'pinepple', 'kiwi']

so I can then use re.search(fruit, list_of_strings) to get only the strings containing fruits, but I’m not sure how to use a list with re.compile. Any suggestions? (I’m not set on using re.compile, but I think regular expressions would be a good way to do this.)

Answer 1

You need to turn your fruit list into the string apple|banana|peach|plum|pineapple|kiwi so that it is a valid regex. The following should do this for you:

fruit_list = ['apple', 'banana', 'peach', 'plum', 'pineapple', 'kiwi']
fruit = re.compile('|'.join(fruit_list))

As ridgerunner pointed out in comments, you will probably want to add word boundaries to the regex, otherwise the regex will match on words like plump since they have a fruit as a substring.

fruit = re.compile(r'\b(?:%s)\b' % '|'.join(fruit_list))

Lastly, if the strings in fruit_list could contain special characters, you will probably want to use re.escape.

'|'.join(map(re.escape, fruit_list))