String function on a pandas series

Question

I wanted to used the below string functions text.lower for a Pandas series instead of from a text file. Tried different methods to convert the series to list and then string,, but no luck. Still I am not able to use the below function directly. Help is much appreciated.

def words(text): 
    return re.findall(r'\w+', text.lower())
WORDS = Counter(words(open('some.txt').read()))

Answer 1

I think need apply by your function:

s = pd.Series(['Aasa dsad d','GTH rr','SSD'])
print (s)
0    Aasa dsad d
1         GTH rr
2            SSD
dtype: object

def words(text): 
    return re.findall(r'\w+', text.lower())

print (s.apply(words))
0    [aasa, dsad, d]
1          [gth, rr]
2              [ssd]
dtype: object

But in pandas is better use str.lower and str.findall , because also working with NaN s:

print (s.str.lower().str.findall(r'\w+'))
0    [aasa, dsad, d]
1          [gth, rr]
2              [ssd]
dtype: object

Answer 2

Something like this?

from collections import Counter
import pandas as pd
series = pd.Series(['word', 'Word', 'WORD', 'other_word'])
counter = Counter(series.apply(lambda x: x.lower()))
print(counter)