利用Pandas向csv文件追加

# -*- coding:utf-8 -*-
import os
import time
import pandas as pd

from multiprocessing import Pool

def merge(filename):
    return pd.read_csv('./fun_data/'+filename)

if __name__  == "__main__":
    file_list = os.listdir('./fun_data')
    e1 = time.time()

    pool = Pool(20)
    result = pool.map(merge,file_list)
    pool.close()
    pool.join()

    e2 = time.time()
    print(e2 - e1)

    for i in result:
        i.to_csv('./static.csv',mode='a',encoding='utf-8’,header=False,index=False)
    e3 = time.time()
    print(e3-e2)

比如：有很多的格式相同的pandas DF需要合并到同一个文件，可以利用这种方式。