Answer 1

Answer 2

Answer 3

一次打开​​多个文件或长文件路径，在多行中分解可能很有用。从@Sven Marnach建议的Python Style Guide评论到另一个答案：

with open('/path/to/InFile.ext', 'r') as file_1, \
     open('/path/to/OutFile.ext', 'w') as file_2:
    file_2.write(file_1.read())

Answer 4

嵌套语句会做同样的工作，在我看来，处理起来会更直接。

让我们说你有inFile.txt，并希望同时将它写入两个outFile。

with open("inFile.txt", 'r') as fr:
    with open("outFile1.txt", 'w') as fw1:
        with open("outFile2.txt", 'w') as fw2:
            for line in fr.readlines():
                fw1.writelines(line)
                fw2.writelines(line)

编辑：

我不理解downvote的原因。我在发布我的答案之前测试了我的代码，它按照需要工作：它写入所有outFile，就像问题一样。没有重复写入或无法写入。所以我很想知道为什么我的答案被认为是错误的，次优的或类似的。

Answer 5

从 Python 3.10 开始，Parenthesized context managers 有一个新功能，它允许使用以下语法：

with (
    open("a", "w") as a,
    open("b", "w") as b
):
    do_something()

Answer 6

从Python 3.3开始，您可以使用ExitStack模块中的类contextlib安全地
打开任意数量的文件。

它可以管理 dynamic 个上下文感知对象，这意味着如果您不知道要处理多少文件，它将非常有用 >。

实际上，文档中提到的规范用例正在管理动态数量的文件。

with ExitStack() as stack:
    files = [stack.enter_context(open(fname)) for fname in filenames]
    # All opened files will automatically be closed at the end of
    # the with statement, even if attempts to open files later
    # in the list raise an exception

---

如果您对这些细节感兴趣，下面是一个通用示例，以说明ExitStack的工作方式：

from contextlib import ExitStack

class X:
    num = 1

    def __init__(self):
        self.num = X.num
        X.num += 1

    def __repr__(self):
        cls = type(self)
        return '{cls.__name__}{self.num}'.format(cls=cls, self=self)

    def __enter__(self):
        print('enter {!r}'.format(self))
        return self.num

    def __exit__(self, exc_type, exc_value, traceback):
        print('exit {!r}'.format(self))
        return True

xs = [X() for _ in range(3)]

with ExitStack() as stack:
    print(len(stack._exit_callbacks)) # number of callbacks called on exit
    nums = [stack.enter_context(x) for x in xs]
    print(len(stack._exit_callbacks))

print(len(stack._exit_callbacks))
print(nums)

输出：

0
enter X1
enter X2
enter X3
3
exit X3
exit X2
exit X1
0
[1, 2, 3]

Answer 7

使用python 2.6它不起作用，我们必须使用以下方式打开多个文件：

with open('a', 'w') as a:
    with open('b', 'w') as b:

Answer 8

最新答案（8年），但是对于希望将多个文件合并为一个文件的人来说，以下功能可能会有所帮助：

def multi_open(_list):
    out=""
    for x in _list:
        try:
            with open(x) as f:
                out+=f.read()
        except:
            pass
            # print(f"Cannot open file {x}")
    return(out)

fl = ["C:/bdlog.txt", "C:/Jts/tws.vmoptions", "C:/not.exist"]
print(multi_open(fl))

---

2018-10-23 19:18:11.361 PROFILE  [Stop Drivers] [1ms]
2018-10-23 19:18:11.361 PROFILE  [Parental uninit] [0ms]
...
# This file contains VM parameters for Trader Workstation.
# Each parameter should be defined in a separate line and the
...