How to Use str.endswith in pandas for String Filtering

Use Series.str.endswith() in pandas to check if each string in a column ends with a specified suffix. It returns a boolean Series that you can use to filter rows or analyze data.

Syntax

The basic syntax of str.endswith() in pandas is:

• Series.str.endswith(pat, na=None)

Where:

• pat is the suffix string or tuple of suffixes to check.
• na defines the boolean value to use for missing values (default is None).

python

Series.str.endswith(pat, na=None)

Example

This example shows how to use str.endswith() to filter a pandas DataFrame for rows where a column's string ends with '.com'.

python

import pandas as pd

data = {'email': ['[e-mail]', '[e-mail]', '[e-mail]', '[e-mail]']}
df = pd.DataFrame(data)

# Check which emails end with '.com'
ends_with_com = df['email'].str.endswith('.com')

# Filter rows where email ends with '.com'
filtered_df = df[ends_with_com]

print(ends_with_com)
print(filtered_df)

Output

0     True
1    False
2     True
3    False
Name: email, dtype: bool
               email
0  [e-mail]
2  [e-mail]

Common Pitfalls

Common mistakes when using str.endswith() include:

• Passing a list instead of a string or tuple as the suffix.
• Not handling missing values, which can cause unexpected NaN results.
• Using it on non-string columns without converting them first.

Always ensure the column is string type and handle na parameter if needed.

python

import pandas as pd

data = {'values': ['apple', None, 'banana', 123]}
df = pd.DataFrame(data)

# Wrong: will raise error or unexpected results
# df['values'].str.endswith(['e', 'a'])  # list instead of string or tuple

# Right: use tuple for multiple suffixes and handle na
result = df['values'].astype(str).str.endswith(('e', 'a'), na=False)
print(result)

Output

0     True
1    False
2     True
3    False
Name: values, dtype: bool

Quick Reference

Parameter	Description
pat	String or tuple of suffixes to check for
na	Boolean value to use for missing data (default None)
Returns	Boolean Series indicating if each string ends with suffix

Key Takeaways

Use Series.str.endswith() to check if strings in a pandas column end with a specific suffix.

Pass a string or tuple of strings as the suffix; do not use a list.

Handle missing values with the na parameter to avoid unexpected results.

Convert non-string columns to string before using str.endswith to prevent errors.

The method returns a boolean Series useful for filtering or analysis.