Pandas — Replace Values

Basic replace

import pandas as pd

df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': ['a', 'b', 'a', 'c']})

# Replace single value
df['A'] = df['A'].replace(1, 10)

# Replace multiple
df['A'] = df['A'].replace({1: 10, 2: 20})

String replace

df['B'] = df['B'].replace({'a': 'alpha', 'b': 'beta'})

With regex

df['B'] = df['B'].replace(r'a', 'alpha', regex=True)

Replace all

df = df.replace(1, 10)  # Replace in all columns

Mini Practice

1. Replace single value
2. Replace multiple values
3. Use regex replacement
4. Replace across columns

Up Next

Continue with Best Practices - Tips and patterns.