Python 2.7如何高效优雅的创建目录和子目录？

Question

我想在我电脑的特定位置创建一堆目录和子目录。我的过程是这样的：

检查是否有同名目录。如果是，请跳过。
如果没有，则在该目录下创建目录和预定义的子目录。

这是我使用 os 模块想出的代码：

def Test():
    main_dir = ["FolderA", "FolderB"] 
    common_dir = ["SubFolder1", "SubFolder2", "SubFolder3"]

    for dir1 in main_dir:
        if not os.path.isdir(dir1):
            for dir2 in common_dir:
                os.makedirs("%s/%s" %(dir1,dir2))

我想知道是否有更好的方法来完成同样的任务（可能更短、更高效、更 pythonic）？

Answer 1

Python 遵循哲学

It is better to ask for forgiveness than to ask for permission.

因此，与其检查 isdir，不如捕获叶目录已经存在时抛出的异常：

def Test():
    main_dir = ["FolderA", "FolderB"] 
    common_dir = ["SubFolder1", "SubFolder2", "SubFolder3"]

    for dir1 in main_dir:
        for dir2 in common_dir:
            try: os.makedirs(os.path.join(dir1,dir2))
            except OSError: pass

您还可以将字符串插值 "%s/%s" %(dir1,dir2) 替换为 os.path.join(dir1, dir2)

另一种更简洁的方法是做笛卡尔积而不是使用两个嵌套的 for 循环：

for dir1, dir2 in itertools.product(main_dir, common_dir):
    try: os.makedirs(os.path.join(dir1,dir2))
    except OSError: pass

Answer 2

怎么样：

import os
from itertools import starmap

def Test():
    main_dir = ["FolderA", "FolderB"] 
    common_dir = ["SubFolder1", "SubFolder2", "SubFolder3"]

    map(os.makedirs, starmap(os.path.join, zip(main_dir, common_dir)))

如果我们担心 os.makedirs() 抛出错误：

import os
from itertools import starmap

def safe_makedirs(*args):
    try:
        return os.makedirs(*args)
    except:
        pass  # Ignore errors; for example if the paths already exist!

def Test():
    main_dir = ["FolderA", "FolderB"] 
    common_dir = ["SubFolder1", "SubFolder2", "SubFolder3"]

    map(safe_makedirs, starmap(os.path.join, zip(main_dir, common_dir)))

Python 2.7如何高效优雅的创建目录和子目录？

How to create directories and sub directories efficiently and elegantly in Python 2.7?

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python-os