counting a special category in python-CodePudding

Hi I have following data frame

S.No   Description    amount
1      a, b, c        100
2      a, c           50
3      b, c           80
4      b, d           90
5      a              150

I want to extract only the counts of a

expected answer:

description
a  3

CodePudding user response：

Use str.count and sum:

df['Description'].str.count('a').sum()

Output: 3

If you want all the counts:

df['Description'].str.split(', ').explode().value_counts()

Output:

a    3
b    3
c    3
d    1
Name: Description, dtype: int64

CodePudding user response：

Check split with explode then value_counts

s = df.Description.str.split(', ').explode().value_counts()
s['a']

Or we do

s = df.Description.str.split(', ',expand=True).eq('a').sum().sum()

CodePudding user response：

df.Description.str.count("a").sum()

Output: 3