count total number of list elements in pandas column

Question

I have a pandas dataframe A with column keywords as (here Im showing only 4 rows but in actual there are millions) :-

 keywords
 ['loans','mercedez','bugatti']
 ['trump','usa']
 ['galaxy','7s','canon','macbook']
 ['beiber','spiderman','marvels','ironmen']

I want to sum total number of list elements in column keywords and store it into some variable. Something like

total_sum=elements in keywords[0]+elements in keywords[1]+elements in 
          keywords[2]+elements in keywords[3]

total_sum=3+2+4+4
total_sum=13

How I can do it in pandas?

Answer 1

IIUC

Setup

df = pd.DataFrame()
df['keywords']=[['loans','mercedez','bugatti'], 
                ['trump','usa'], 
                ['galaxy','7s','canon','macbook'], 
                ['beiber','spiderman','marvels','ironmen']]

Then juse use str.len and sum

df.keywords.str.len().sum()

---

Detail:

df.keywords.str.len()

0    3
1    2
2    4
3    4
Name: keywords, dtype: int64

---

Ps: If you have strings that look like a list, use ast.literal_eval to convert to list first.

df.keywords.transform(ast.literal_eval).str.len().sum()

Answer 2

You can try this one:

df.keywords.map(len).sum()