Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Regular Expressions in Python Introduction to Regular Expressions Word Length

Regular Expression for Words of a Certain Length

When I try the attached code in the interpreter, it works. When I try in the Treehouse Workspace, I get an error saying "object of type 'NoneType" has no len(). This makes me think the function is returning an empty list. Any advice why?

word_length.py
import re

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

def find_words(count,search_string):
  count_string = str(count)
  re.findall(r"\w{"+count_string+",}",search_string)

2 Answers

Dan Johnson
Dan Johnson
40,533 Points

Your logic all checks out, you're just getting NoneType since you forgot to add in the return keyword.

Makes sense - and now it works. Thanks Dan!