我想将许多文件视为一个文件.什么是正确的pythonic方式采用[filenames] => [文件对象] => [行]与生成器/不读取整个文件到内存?
我们都知道打开文件的正确方法:
with open("auth.log", "rb") as f:
print sum(f.readlines())
Run Code Online (Sandbox Code Playgroud)
我们知道将几个迭代器/生成器链接到一个长迭代器的正确方法:
>>> list(itertools.chain(range(3), range(3)))
[0, 1, 2, 0, 1, 2]
Run Code Online (Sandbox Code Playgroud)
但是如何将多个文件链接在一起并保留上下文管理器?
with open("auth.log", "rb") as f0:
with open("auth.log.1", "rb") as f1:
for line in itertools.chain(f0, f1):
do_stuff_with(line)
# f1 is now closed
# f0 is now closed
# gross
Run Code Online (Sandbox Code Playgroud)
我可以忽略上下文管理器并执行类似的操作,但感觉不对:
files = itertools.chain(*(open(f, "rb") for f in file_names))
for line in files:
do_stuff_with(line)
Run Code Online (Sandbox Code Playgroud)
或者这是Async IO-PEP 3156的用途,我只需要等待优雅的语法?