python 同時讀取多個檔案__python

Python中開啟文本使用的是 with語句，比如開啟一個檔案並讀取每一行

with open(filename) as fp:    for line in fp:        # do something

為了同時讀取多個檔案，可以使用下面的代碼

with open(filename1) as fp1, open(filename2) as fp2, open(filename3) as fp3:    for l1 in fp1:        l2 = fp2.readline()        l3 = fp3.readline()        # do something

稍微簡介一點可以使用contextlib中的nested，有

from contextlib import nestedwith nested(open(filename1), open(filename2), open(filename3)) as (fp1, fp2, fp3):    for l1 in fp1:        l2 = fp2.readline()        l3 = fp3.readline()        # do something