p functionality in Python

This question already has an answer here:

How can I create a directory if it does not exist? 26 answers

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mkdir -p functionality as follows:

import errno    
import os


def mkdir_p(path):
    try:
        os.makedirs(path)
    except OSError as exc:  # Python >2.5
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise

Update

For Python ≥ 3.2, os.makedirs has an optional third argument exist_ok that, when true, enables the mkdir -p functionality —unless mode is provided and the existing directory has different permissions than the intended ones; in that case, OSError is raised as previously.

Update 2

For Python ≥ 3.5, there is also pathlib.Path.mkdir :

import pathlib

pathlib.Path("/tmp/path/to/desired/directory").mkdir(parents=True, exist_ok=True)

The exist_ok parameter was added in Python 3.5.

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In Python >=3.2, that's

os.makedirs(path, exist_ok=True)

In earlier versions, use @tzot's answer.

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This is easier than trapping the exception:

import os
if not os.path.exists(...):
    os.makedirs(...)

Disclaimer This approach requires two system calls which is more susceptible to race conditions under certain environments/conditions. If you're writing something more sophisticated than a simple throwaway script running in a controlled environment, you're better off going with the accepted answer that requires only one system call.

UPDATE 2012-07-27

I'm tempted to delete this answer, but I think there's value in the comment thread below. As such, I'm converting it to a wiki.

链接地址: http://www.djcxy.com/p/9264.html

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