如何组合 Python 中多个文件夹中的多个 CSV 文件？

Question

I have several CSV files each represents data for a day with no header. more like month-1/day-1.csv... day-30.csv - month-2/day-1.csv..? etc how can I combine all of these CSV files into one big CSV file that contains all of them?

Answer 1

Hi quant and welcome to SO!

You can use following code to do this:

import os
import glob
import pandas as pd

path = '/your_directory_containing the files'
os.chdir(path)

all_filenames = [i for i in glob.glob('*.{}'.format('csv'))]

combined_csv = pd.concat([pd.read_csv(f) for f in all_filenames ])
combined_csv.to_csv( "combined_csv.csv", index=False, encoding='utf-8-sig')

Please note, that this code will combine all .csv -files in the specified directory.

I hope the code works for you:)

Answer 2

This assumes that your input is in a in_data folder and the output goes into a folder called out_data and both folders are in the directory of your notebook.

import pandas as pd
import glob

dfs = pd.concat([pd.read_csv(f, header=None) for f in glob.glob("./in_data/month*/day*")])
dfs.to_csv("./out_data/df_combined.csv", index=False)