Pandas: Find the index of a given substring of a DataFrame column

Last update on April 03 2025 12:56:34 (UTC/GMT +8 hours)

7. Find Substring Index

Write a Pandas program to find the index of a given substring of a DataFrame column.

Sample Solution:

Python Code :

import pandas as pd
df = pd.DataFrame({
    'name_code': ['c001','c002','c022', 'c2002', 'c2222'],
    'date_of_birth ': ['12/05/2002','16/02/1999','25/09/1998','12/02/2022','15/09/1997'],
    'age': [18.5, 21.2, 22.5, 22, 23]
})
print("Original DataFrame:")
print(df)
print("\nCount occurrence of 22 in date_of_birth column:")
df['Index'] = list(map(lambda x: x.find('22'), df['name_code']))
print(df)

Sample Output:

Original DataFrame:
  name_code date_of_birth    age
0      c001     12/05/2002  18.5
1      c002     16/02/1999  21.2
2      c022     25/09/1998  22.5
3     c2002     12/02/2022  22.0
4     c2222     15/09/1997  23.0

Count occurrence of 22 in date_of_birth column:
  name_code date_of_birth    age  Index
0      c001     12/05/2002  18.5     -1
1      c002     16/02/1999  21.2     -1
2      c022     25/09/1998  22.5      2
3     c2002     12/02/2022  22.0     -1
4     c2222     15/09/1997  23.0      1

For more Practice: Solve these Related Problems:

• Write a Pandas program to locate the index of the first occurrence of a specified substring in a DataFrame column using vectorized methods.
• Write a Pandas program to search for a substring in a DataFrame column and return the index position for each row where it occurs.
• Write a Pandas program to identify the position of a given substring within each string of a column and output a series of indices.
• Write a Pandas program to create a new series containing the index positions of a substring's first appearance in each row of a column.

Python Code Editor:

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