Pandas DataFrame.keys

The DataFrame.keys method in pandas is used to retrieve the column labels (names) of a DataFrame. It is a shorthand for accessing the column labels using the columns attribute.

Syntax

The syntax for DataFrame.keys is:

DataFrame.keys()

Here, DataFrame refers to the pandas DataFrame whose column labels are being retrieved.

Returns

A pandas Index object containing the column labels of the DataFrame.

Examples

Retrieving Column Labels

Use keys to get the column labels of a DataFrame.

Python Program

import pandas as pd

# Create a DataFrame
data = {
    'Name': ['Arjun', 'Ram', 'Priya'],
    'Age': [25, 30, 35],
    'Salary': [70000.5, 80000.0, 90000.0]
}
df = pd.DataFrame(data)

# Get the column labels
print("Column Labels:")
print(df.keys())

Output

Column Labels:
Index(['Name', 'Age', 'Salary'], dtype='object')

Accessing Column Labels as a List

Convert the result of keys to a list for easier manipulation.

Python Program

import pandas as pd

# Create a DataFrame
data = {
    'Name': ['Arjun', 'Ram', 'Priya'],
    'Age': [25, 30, 35],
    'Salary': [70000.5, 80000.0, 90000.0]
}
df = pd.DataFrame(data)

# Get the column labels as a list
print("Column Labels as List:")
column_labels = list(df.keys())
print(column_labels)

Output

Column Labels as List:
['Name', 'Age', 'Salary']

Iterating Over Column Labels

Iterate through the column labels using keys.

Python Program

import pandas as pd

# Create a DataFrame
data = {
    'Name': ['Arjun', 'Ram', 'Priya'],
    'Age': [25, 30, 35],
    'Salary': [70000.5, 80000.0, 90000.0]
}
df = pd.DataFrame(data)

# Iterate over column labels
print("Iterating Over Column Labels:")
for key in df.keys():
    print(key)

Output

Iterating Over Column Labels:
Name
Age
Salary

Comparing `keys` and `columns`

The keys method is equivalent to the columns attribute. Both return the column labels.

Python Program

import pandas as pd

# Create a DataFrame
data = {
    'Name': ['Arjun', 'Ram', 'Priya'],
    'Age': [25, 30, 35],
    'Salary': [70000.5, 80000.0, 90000.0]
}
df = pd.DataFrame(data)

# Compare keys() and columns
print("Using keys():")
print(df.keys())
print("\nUsing columns:")
print(df.columns)

Output

Using keys():
Index(['Name', 'Age', 'Salary'], dtype='object')

Using columns:
Index(['Name', 'Age', 'Salary'], dtype='object')

Summary

In this tutorial, we explored the DataFrame.keys method in pandas. Key takeaways include:

Using keys to retrieve the column labels of a DataFrame.
Converting the result to a list for easier manipulation.
Iterating over the column labels.
Understanding that keys is equivalent to columns.

The DataFrame.keys method is a simple and effective way to access column labels in pandas DataFrames.