Combine Province, City, and District Columns in Pandas with Vectorized Operations

Introduction

Hello, I'm Pipi. During the National Day holiday I asked a pandas data‑processing question in a Python community, as shown in the screenshot below.

Implementation

The solution uses vectorized operations. Two code snippets are provided.

import pandas as pd
df = pd.read_excel('test.xlsx')
# Method 1, direct construction
df['标记'] = df.省.astype('str') + '-' + df.市.astype('str') + '-' + df.区.astype('str')
# Method 2, using concat function
df['new'] = df["省"].map(str).str.cat([df["市"].map(str), df["区"].map(str)], sep='-', na_rep='?')
print(df)

Running the code produces the following result:

Another user also shared an alternative implementation, illustrated below:

Conclusion

This article demonstrates how to solve a common pandas problem by concatenating province, city, and district columns using vectorized string operations, providing clear code and output to help readers apply the technique.