Swap Odd and Even Columns in a Pandas DataFrame – 3 Quick Methods

1. Introduction

The task is to swap the odd‑numbered columns with the even‑numbered columns in a pandas DataFrame, e.g., turning columns A, B into B, A.

en = 'abcdef'
df = pd.DataFrame([[i + j for j in list(en)] for i in list(en)], columns=list(en.upper()), index=list(en.upper()))
print('源数据')
print(df)
# Please complete the code
print('转换后')
print(df)

Original data:

Result after swapping:

2. Implementation

Method 1

Kiddo’s solution swaps columns using direct indexing. The code and its output are shown below.

Method 2

MoonGod simplified the approach to a one‑liner that reorders columns based on their index.

df = df[[df.columns[index + (-1) ** index] for index in range(len(df.columns))]]

Result:

Method 3

MoonGod provided another concise solution using NumPy to flatten a reordered column list.

import numpy as np
import pandas as pd
# Data is prepared above; complete the remaining code to achieve the swap.
en = 'abcdef'
df = pd.DataFrame([[i + j for j in list(en)] for i in list(en)], columns=list(en.upper()), index=list(en.upper()))
print('源数据')
print(df)
# Please complete the code
df = df[np.array((df.columns[1::2], df.columns[::2])).flatten('F')]
print('转换后')
print(df)

Result:

3. Summary

The article presented three practical Python methods to interchange odd and even columns in a pandas DataFrame, each with full code and visual verification, enabling readers to choose the approach that best fits their workflow.