CODEWITHSUNDEEP
pythonpandascount
Arsh Singh
Arsh Singh

Reputation: 87

How to count values in column

I have a data frame name df and I want to count '|' and '/' in name1 & name2 respectively.

id name1    name2
1  a|b      a/b
2  a|b|c    a/b/c
3  a        a
4  a|b|c|d  a/b/c/d

This is the code

[In] 1: import pandas as pd

        data = {'id' : pd.Series([1, 2, 3, 4]),
                'name1': pd.Series(['a|b', 'a|b|c', 'a', 'a|b|c|d']), 
                'name2': pd.Series(['a/b', 'a/b/c', 'a', 'a/b/c/d'])}
        df = pd.DataFrame(data)

[In] 2: df['name1'].str.count('|')
[Out] 2: 4
         6
         2
         8
[In] 3: df['name2'].str.count('/')
[Out] 3: 1
         2
         0
         3

The problem which I am facing is it gives correct output for 3 but for 2 it gives incorrect.
Note: I want to count '|' separately because in original data only '|' this is present not '/'.

Upvotes: 2

Views: 60

Answers (1)

jezrael
jezrael

Reputation: 863541

Problem is | is regex special character, so necessary escaping by \:

a = df['name1'].str.count('\|')
print (a)
0    1
1    2
2    0
3    3
Name: name1, dtype: int64

If check Series.str.count:

Count occurrences of pattern in each string of the Series/Index.

This function is used to count the number of times a particular regex pattern is repeated in each of the string elements of the Series.

Upvotes: 1

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