How to Concatenate Multiple CSV files in Python

Assume that you have multiple CSV files located in a specific folder, and you want to concatenate all of them and saved them to a file called merged.csv. We can work with Pandas and use the trick with mode=a within the .to_csv() which means append.

import os
import pandas as pd

# iterate over all files within "My_Folder"
for file in os.listdir("My_Folder"):
    if file.endswith(".csv"):
        tmp = pd.read_csv(os.path.join("My_Folder", file))
        tmp.to_csv("merged.csv", index=False, header=False, mode='a')