python - 在 python 2.6 中逐行迭代两个文件的首选方法

Question

这个问题已经有答案了:

Multiple context `with` statement in Python 2.6 (1 个回答)

已关闭 8 年前。

在 Python 2.7之后，可以使用类似 this 的解决方案逐行迭代两个文件。但是，在早期版本的 Python 中，这不起作用并会给出无效语法错误。

我想知道使用 Python 2.6 执行此操作的最佳方法？

Answer 1

首选方式仍然相同，但 with 语句不支持单个语句中的多个对象。所以，你可能想像这样分割它

from itertools import izip

with open("Input1.txt") as textfile1: 
    with open("Input2.txt") as textfile2:
        for x, y in izip(textfile1, textfile2):

根据PEP-0343 ，“规范:‘with’语句”部分，

A new statement is proposed with the syntax:

   with EXPR as VAR:
       BLOCK

Here, with and as are new keywords; EXPR is an arbitrary expression (but not an expression-list) and VAR is a single assignment target. It can not be a comma-separated sequence of variables, but it can be a parenthesized comma-separated sequence of variables. (This restriction makes a future extension possible of the syntax to have multiple comma-separated resources, each with its own optional as-clause.)