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Python Regular Expressions in Python Introduction to Regular Expressions Word Length

Not sure what I'm doing wrong

The instructions: Create a function named find_words that takes a count and a string. Return a list of all of the words in the string that are count word characters long or longer.

I know num is becoming part of the string, but I'm not sure how else to do this.

import re

def find_words (num, my_string):
    my_list= []
    my_list.append(re.findall(r'\w{num,}', my_string))
    return my_list
# >>> find_words(4, "dog, cat, baby, balloon, me")
# ['baby', 'balloon']

2 Answers

Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

There are two issues.

  • num Needs to be formatted into the regex. Currently it's just the characters "num"

  • re.findall() returns a list so it doesn't need to be appended into another list. Simply assign the results to my_list


word_list = (re.findall(r'\w{{},}'.format(count), string))


Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

Michael, format can be confused by the regex braces vs the format placeholders. The regex braces need to escaped by doubling them:


which can become hard to read.

Thanks, Chris!