Pandas: Check whether only lower case or upper case is present in a given column of a DataFrame

Last update on May 02 2025 12:51:31 (UTC/GMT +8 hours)

12. Check Case Consistency (Lower/Upper)

Write a Pandas program to check whether only lower case or upper case is present in a given column of a DataFrame.

Sample Solution:

Python Code :

import pandas as pd
df = pd.DataFrame({
    'company_code': ['ABCD','EFGF', 'hhhh', 'abcd', 'EAWQaaa'],
    'date_of_sale ': ['12/05/2002','16/02/1999','25/09/1998','12/02/2022','15/09/1997'],
    'sale_amount': [12348.5, 233331.2, 22.5, 2566552.0, 23.0]})

print("Original DataFrame:")
print(df)
print("\nIs lower (company_code)?")
df['company_code_ul_cases'] = list(map(lambda x: x.islower(), df['company_code']))
print(df)
print("\nIs Upper (company_code)?")
df['company_code_ul_cases'] = list(map(lambda x: x.isupper(), df['company_code']))
print(df)

Sample Output:

Original DataFrame:
  company_code date_of_sale   sale_amount
0         ABCD    12/05/2002      12348.5
1         EFGF    16/02/1999     233331.2
2         hhhh    25/09/1998         22.5
3         abcd    12/02/2022    2566552.0
4      EAWQaaa    15/09/1997         23.0

Is lower (company_code)?
  company_code          ...          company_code_ul_cases
0         ABCD          ...                          False
1         EFGF          ...                          False
2         hhhh          ...                           True
3         abcd          ...                           True
4      EAWQaaa          ...                          False

[5 rows x 4 columns]

Is Upper (company_code)?
  company_code          ...          company_code_ul_cases
0         ABCD          ...                           True
1         EFGF          ...                           True
2         hhhh          ...                          False
3         abcd          ...                          False
4      EAWQaaa          ...                          False

[5 rows x 4 columns]

For more Practice: Solve these Related Problems:

Write a Pandas program to verify if each element in a DataFrame column is entirely in lower case or upper case.
Write a Pandas program to create a boolean series that checks if the strings in a column are either all lower or all upper case.
Write a Pandas program to test whether each element in a column is in lower case and then output the result for mixed-case strings.
Write a Pandas program to compare the original column with its lower and upper case transformations and then identify inconsistent cases.

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Python Code Editor:

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