value_counts can't count values in list.

Hi, Some of the columns in my dataframe have a list.

When i use value_counts() ; i get this result:

But i want this results:

Is there any code for it?

CodePudding user response：

I think explode will work for you

import pandas as pd
df = pd.DataFrame({"a": [['A'], ['A', 'O'], ['B'], ['A', 'AB', 'O'], ['A']]})
df["a"].explode().value_counts()

# output
A     4
O     2
B     1
AB    1

# If your dataframe is like this
from ast import literal_eval
df = pd.DataFrame({"a": ["['A']", "['A', 'O']", "['B']", "['A', 'AB', 'O']", "['A']"]})
df["a"].apply(literal_eval).explode().value_counts()

CodePudding user response：

You could collect the lists, unpack the items (using itertools.chain) and then count (using collections.Counter) and put it back into a pandas object

from itertools import chain
from collections import Counter
df['Y'] = df['Y'].apply(lambda x: eval(x)) #converts to list
pd.Series(Counter(chain.from_iterable(df['Y'].values)))

Output

A     4
O     2
B     1
AB    1