I need to write function which takes a count and a string and return a list of all of the words in the string that are count word characters long or longer.
My function is:
import re
def find_words(count, a_str):
count = int(count)
return re.findall(r'\w{},'.format(int(count)), a_str)
But it doesn't work, it is return empty list:
Example:
find_words(4, "dog, cat, baby, balloon, me")
Should return:
['baby', 'balloon']
The regex isn't correct. The {} is interpreted as placeholder for format, but you want it to be the regexs' {} which specifies the number of repeats. You need to use r'\w{{{}}}' here. Observe the difference:
>>> r'\w{},'.format(4)
'\\w4,'
>>> r'\w{{{},}}'.format(4)
'\\w{4,}'
And then it works correctly:
import re
def find_words(count, a_str):
count = int(count)
return re.findall(r'\w{{{},}}'.format(count), a_str)
>>> find_words(4, "dog, cat, baby, balloon, me")
['baby', 'balloon']
{{ and }}." "Format String Syntax" And you want to keep one brace character in the literal text for the regex but you also want to insert the count. So {{ so it keeps the { and one { for the formatting.Why RegExp?
>>> string = "dog, cat, baby, balloon, me"
>>> [word for word in string.split(', ') if len(word) >= 4]
['baby', 'balloon']
So function could be something like follow:
>>> def find_words(count, a_str):
... return [word for word in a_str.split(', ') if len(word) >= count]
...
>>> find_words(4, 'dog, cat, baby, balloon, me')
['baby', 'balloon']
You can try this:
def find_words(count, a_str):
s = [re.findall("\w{"+str(count)+",}", i) for i in ["dog, cat, baby, balloon, me"]]
return s[0]
print(find_words(4, ["dog, cat, baby, balloon, me"]))
Output:
['baby', 'balloon']
