迭代跨越線路中的序列

Question

兩個文件我有兩個文件，我想（一個接一個）跨均進行了一些行明智的操作。我現在使用兩個循環來實現這一點。有沒有辦法做到在一個循環（在Python 2.7）：

for fileName in [fileNam1,fileName2]: 
    for line in open(fileName): 
     do something 

Answer 1

正如已指出itertools.chain是一種選擇，但也有其避免了明確地使用open另一個有用的標準模塊...

import fileinput 
for line in fileinput.input(['file1.txt', 'file2.txt']): 
    print line 

這也有行號一些方便的功能和文件名等...查看該文檔在http://docs.python.org/library/fileinput.html

在回覆評論 - 與上下文管理

012使用

from contextlib import closing 

with closing(fileinput.input(['file1.txt', 'file2.txt'])) as infiles: 
    for line in infiles: 
     pass # stuff 

Answer 2

的itertools模塊具有隻是一個工具。試試這個：

import itertools 

for line in itertools.chain(open(file_name1), open(file_name2)): 
    # do something 

Answer 3

也許你可以使用列表理解或映射避免內環，減少，過濾器等，這一切都取決於你的需要。你想做什麼？

Answer 4

不正是你所要求的，但中的FileInput模塊可能是有用的。

 
"""Helper class to quickly write a loop over all standard input files. 

Typical use is: 

    import fileinput 
    for line in fileinput.input(): 
     process(line) 

This iterates over the lines of all files listed in sys.argv[1:], 
defaulting to sys.stdin if the list is empty. If a filename is '-' it 
is also replaced by sys.stdin. To specify an alternative list of 
filenames, pass it as the argument to input(). A single file name is 
also allowed. 

Functions filename(), lineno() return the filename and cumulative line 
number of the line that has just been read; filelineno() returns its 
line number in the current file; isfirstline() returns true iff the 
line just read is the first line of its file; isstdin() returns true 
iff the line was read from sys.stdin. Function nextfile() closes the 
current file so that the next iteration will read the first line from 
the next file (if any); lines not read from the file will not count 
towards the cumulative line count; the filename is not changed until 
after the first line of the next file has been read. Function close() 
closes the sequence. 
... 

Answer 5

這是我的第一個回答，請對不起任何錯誤

>>> file1 = open('H:\\file-1.txt') 
>>> file2 = open('H:\\file-2.txt') 
>>> for i, j in map(None, file1.readlines(), file2.readlines()): 
     print i,j