Not Sure..Regex

Question

Not sure what's wrong here, can anyone offer a hand?
```word_length.py
import re
EXAMPLE:
>>> find_words(4, "dog, cat, baby, balloon, me")
['baby', 'balloon']
def find_words(acount, mstr):
  return re.findall(r"\w{acount,},", mstr)
```

Iain Simmons · Answer

You can use/interpolate variables inside quoted strings, but you'll run into issues trying to use str.format and its curly braces inside the regex curly braces.
One other option besides @Adiv Abramson (http://teamtreehouse.com/adivabramson)'s solution is to use the old string interpolation syntax:
python
def find_words(acount, mstr):
  return re.findall(r"\w{%s,}" % acount, mstr)

Note that you shouldn't have the trailing comma at the end of your regular expression string because you want to be able to match the last word in the quoted string if necessary.

Adiv Abramson · Answer

I believe the problem with your regex, 
re.findall(r"\w{acount,},", mstr) is that Python doesn't substitute the value of the acount variable where the variable name appears in the regex. I would try something like this:
return re.findall(r'\w{' + str(acount) + ',}',mstr)
Unlike Perl, Python doesn't interpolate variables embedded in a quoted string.

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Gregg Mojica

Gregg Mojica

Not Sure..Regex

2 Answers

Iain Simmons

Iain Simmons

Adiv Abramson

Adiv Abramson