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Python Regular Expressions in Python Introduction to Regular Expressions Word Length

Posted by chen liu
chen liu
3,188 Points

I couldn't understand the answer executable.

what do the double "+" mean in the answer executable.

word_length.py 
import re

# EXAMPLE:
# >>> find_words(4, "dog, cat, baby, balloon, me")
# ['baby', 'balloon']




return re.findall(r'\w{str(count) ,}', string) #<-- cast count as string
#This is the right answer, but I cound't understand waht the"+" in "+str(count)+" means?
return re.findall(r'\w{'+ str(count) + ',}', string) #<-- cast count as string

1 Answer

Jeff Muday
MOD
Jeff Muday
Treehouse Moderator 28,722 Points
Jeff Muday
Jeff Muday
Treehouse Moderator 28,722 Points

Basically, the plus signs allow you to EMBED the count as a string value inside the regular expression.

the \w allows the "capture" of letters or digits and the braces {} show how many letters to capture

count = 4 makes the regular expression below (which allows finding words with 4 characters or more)

r'\w{4}'

count = 5 yields the expression below (which allows finding words with 5 characters or more)

r'\w{5}