如何仅列出Python中的顶级目录?

问题:如何仅列出Python中的顶级目录?

我希望仅列出某个文件夹内的目录。这意味着我既不需要列出文件名,也不需要其他子文件夹。

让我们看看一个例子是否有帮助。在当前目录中,我们有:

>>> os.listdir(os.getcwd())
['cx_Oracle-doc', 'DLLs', 'Doc', 'include', 'Lib', 'libs', 'LICENSE.txt', 'mod_p
ython-wininst.log', 'NEWS.txt', 'pymssql-wininst.log', 'python.exe', 'pythonw.ex
e', 'README.txt', 'Removemod_python.exe', 'Removepymssql.exe', 'Scripts', 'tcl',
 'Tools', 'w9xpopen.exe']

但是,我不想列出文件名。我也不需要子文件夹,例如\ Lib \ curses。本质上,我想要的东西适用于以下情况:

>>> for root, dirnames, filenames in os.walk('.'):
...     print dirnames
...     break
...
['cx_Oracle-doc', 'DLLs', 'Doc', 'include', 'Lib', 'libs', 'Scripts', 'tcl', 'Tools']

但是,我想知道是否有一种更简单的方法来获得相同的结果。我得到的印象是仅使用os.walk返回顶级是无效的/太多了。

I want to be able to list only the directories inside some folder. This means I don’t want filenames listed, nor do I want additional sub-folders.

Let’s see if an example helps. In the current directory we have:

>>> os.listdir(os.getcwd())
['cx_Oracle-doc', 'DLLs', 'Doc', 'include', 'Lib', 'libs', 'LICENSE.txt', 'mod_p
ython-wininst.log', 'NEWS.txt', 'pymssql-wininst.log', 'python.exe', 'pythonw.ex
e', 'README.txt', 'Removemod_python.exe', 'Removepymssql.exe', 'Scripts', 'tcl',
 'Tools', 'w9xpopen.exe']

However, I don’t want filenames listed. Nor do I want sub-folders such as \Lib\curses. Essentially what I want works with the following:

>>> for root, dirnames, filenames in os.walk('.'):
...     print dirnames
...     break
...
['cx_Oracle-doc', 'DLLs', 'Doc', 'include', 'Lib', 'libs', 'Scripts', 'tcl', 'Tools']

However, I’m wondering if there’s a simpler way of achieving the same results. I get the impression that using os.walk only to return the top level is inefficient/too much.


回答 0

使用os.path.isdir()过滤结果(并使用os.path.join()获得真实路径):

>>> [ name for name in os.listdir(thedir) if os.path.isdir(os.path.join(thedir, name)) ]
['ctypes', 'distutils', 'encodings', 'lib-tk', 'config', 'idlelib', 'xml', 'bsddb', 'hotshot', 'logging', 'doc', 'test', 'compiler', 'curses', 'site-packages', 'email', 'sqlite3', 'lib-dynload', 'wsgiref', 'plat-linux2', 'plat-mac']

Filter the result using os.path.isdir() (and use os.path.join() to get the real path):

>>> [ name for name in os.listdir(thedir) if os.path.isdir(os.path.join(thedir, name)) ]
['ctypes', 'distutils', 'encodings', 'lib-tk', 'config', 'idlelib', 'xml', 'bsddb', 'hotshot', 'logging', 'doc', 'test', 'compiler', 'curses', 'site-packages', 'email', 'sqlite3', 'lib-dynload', 'wsgiref', 'plat-linux2', 'plat-mac']

回答 1

步行

os.walknext项目功能一起使用:

next(os.walk('.'))[1]

对于Python <= 2.5,请使用:

os.walk('.').next()[1]

如何运作

os.walk是一个生成器,调用next将以3元组(目录路径,目录名,文件名)的形式获取第一个结果。因此,[1]索引仅返回dirnames该元组的。

os.walk

Use os.walk with next item function:

next(os.walk('.'))[1]

For Python <=2.5 use:

os.walk('.').next()[1]

How this works

os.walk is a generator and calling next will get the first result in the form of a 3-tuple (dirpath, dirnames, filenames). Thus the [1] index returns only the dirnames from that tuple.


回答 2

使用os.path.isdir筛选列表以检测目录。

filter(os.path.isdir, os.listdir(os.getcwd()))

Filter the list using os.path.isdir to detect directories.

filter(os.path.isdir, os.listdir(os.getcwd()))

回答 3

directories=[d for d in os.listdir(os.getcwd()) if os.path.isdir(d)]
directories=[d for d in os.listdir(os.getcwd()) if os.path.isdir(d)]

回答 4

请注意,os.listdir(os.getcwd())最好不要这样做,而要这样做os.listdir(os.path.curdir)。少调用一个函数,它具有可移植性。

因此,要完成答案,请获取文件夹中的目录列表:

def listdirs(folder):
    return [d for d in os.listdir(folder) if os.path.isdir(os.path.join(folder, d))]

如果您希望使用完整路径名,请使用以下功能:

def listdirs(folder):
    return [
        d for d in (os.path.join(folder, d1) for d1 in os.listdir(folder))
        if os.path.isdir(d)
    ]

Note that, instead of doing os.listdir(os.getcwd()), it’s preferable to do os.listdir(os.path.curdir). One less function call, and it’s as portable.

So, to complete the answer, to get a list of directories in a folder:

def listdirs(folder):
    return [d for d in os.listdir(folder) if os.path.isdir(os.path.join(folder, d))]

If you prefer full pathnames, then use this function:

def listdirs(folder):
    return [
        d for d in (os.path.join(folder, d1) for d1 in os.listdir(folder))
        if os.path.isdir(d)
    ]

回答 5

这似乎也起作用(至少在Linux上):

import glob, os
glob.glob('*' + os.path.sep)

This seems to work too (at least on linux):

import glob, os
glob.glob('*' + os.path.sep)

回答 6

只是要补充一点,使用os.listdir()不会“比非常简单的os.walk()。next()[1]花费更多的处理时间”)。这是因为os.walk()在内部使用os.listdir()。实际上,如果您一起测试它们:

>>>> import timeit
>>>> timeit.timeit("os.walk('.').next()[1]", "import os", number=10000)
1.1215229034423828
>>>> timeit.timeit("[ name for name in os.listdir('.') if os.path.isdir(os.path.join('.', name)) ]", "import os", number=10000)
1.0592019557952881

os.listdir()的过滤非常快。

Just to add that using os.listdir() does not “take a lot of processing vs very simple os.walk().next()[1]”. This is because os.walk() uses os.listdir() internally. In fact if you test them together:

>>>> import timeit
>>>> timeit.timeit("os.walk('.').next()[1]", "import os", number=10000)
1.1215229034423828
>>>> timeit.timeit("[ name for name in os.listdir('.') if os.path.isdir(os.path.join('.', name)) ]", "import os", number=10000)
1.0592019557952881

The filtering of os.listdir() is very slightly faster.


回答 7

一种非常简单而优雅的方法是使用此方法:

 import os
 dir_list = os.walk('.').next()[1]
 print dir_list

在需要文件夹名称的同一文件夹中运行此脚本,它将仅为您提供直接的文件夹名称(也没有文件夹的完整路径)。

A very much simpler and elegant way is to use this:

 import os
 dir_list = os.walk('.').next()[1]
 print dir_list

Run this script in the same folder for which you want folder names.It will give you exactly the immediate folders name only(that too without the full path of the folders).


回答 8

使用列表理解

[a for a in os.listdir() if os.path.isdir(a)]

我认为这是最简单的方法

Using list comprehension,

[a for a in os.listdir() if os.path.isdir(a)]

I think It is the simplest way


回答 9

作为一个新手,我还不能直接发表评论,但这是我想补充到ΤζΩΤζΙΟΥ的以下部分的一个小更正:

如果您希望使用完整路径名,请使用以下功能:

def listdirs(folder):  
  return [
    d for d in (os.path.join(folder, d1) for d1 in os.listdir(folder))
    if os.path.isdir(d)
]

对于仍然使用python <2.4的用户:内部构造需要是列表而不是元组,因此应如下所示:

def listdirs(folder):  
  return [
    d for d in [os.path.join(folder, d1) for d1 in os.listdir(folder)]
    if os.path.isdir(d)
  ]

否则会出现语法错误。

being a newbie here i can’t yet directly comment but here is a small correction i’d like to add to the following part of ΤΖΩΤΖΙΟΥ’s answer :

If you prefer full pathnames, then use this function:

def listdirs(folder):  
  return [
    d for d in (os.path.join(folder, d1) for d1 in os.listdir(folder))
    if os.path.isdir(d)
]

for those still on python < 2.4: the inner construct needs to be a list instead of a tuple and therefore should read like this:

def listdirs(folder):  
  return [
    d for d in [os.path.join(folder, d1) for d1 in os.listdir(folder)]
    if os.path.isdir(d)
  ]

otherwise one gets a syntax error.


回答 10

[x for x in os.listdir(somedir) if os.path.isdir(os.path.join(somedir, x))]
[x for x in os.listdir(somedir) if os.path.isdir(os.path.join(somedir, x))]

回答 11

有关完整路径名的列表,相对于其他解决方案,我更喜欢此版本:

def listdirs(dir):
    return [os.path.join(os.path.join(dir, x)) for x in os.listdir(dir) 
        if os.path.isdir(os.path.join(dir, x))]

For a list of full path names I prefer this version to the other solutions here:

def listdirs(dir):
    return [os.path.join(os.path.join(dir, x)) for x in os.listdir(dir) 
        if os.path.isdir(os.path.join(dir, x))]

回答 12

scanDir = "abc"
directories = [d for d in os.listdir(scanDir) if os.path.isdir(os.path.join(os.path.abspath(scanDir), d))]
scanDir = "abc"
directories = [d for d in os.listdir(scanDir) if os.path.isdir(os.path.join(os.path.abspath(scanDir), d))]

回答 13

没有目录时不会失败的更安全的选项。

def listdirs(folder):
    if os.path.exists(folder):
         return [d for d in os.listdir(folder) if os.path.isdir(os.path.join(folder, d))]
    else:
         return []

A safer option that does not fail when there is no directory.

def listdirs(folder):
    if os.path.exists(folder):
         return [d for d in os.listdir(folder) if os.path.isdir(os.path.join(folder, d))]
    else:
         return []

回答 14

这样吗

>>>> [path for path in os.listdir(os.getcwd()) if os.path.isdir(path)]

Like so?

>>>> [path for path in os.listdir(os.getcwd()) if os.path.isdir(path)]

回答 15

蟒3.4引入pathlib模块到标准库,它提供了一个面向对象的方法来处理的文件系统的路径:

from pathlib import Path

p = Path('./')
[f for f in p.iterdir() if f.is_dir()]

Python 3.4 introduced the pathlib module into the standard library, which provides an object oriented approach to handle filesystem paths:

from pathlib import Path

p = Path('./')
[f for f in p.iterdir() if f.is_dir()]

回答 16

-- This will exclude files and traverse through 1 level of sub folders in the root

def list_files(dir):
    List = []
    filterstr = ' '
    for root, dirs, files in os.walk(dir, topdown = True):
        #r.append(root)
        if (root == dir):
            pass
        elif filterstr in root:
            #filterstr = ' '
            pass
        else:
            filterstr = root
            #print(root)
            for name in files:
                print(root)
                print(dirs)
                List.append(os.path.join(root,name))
            #print(os.path.join(root,name),"\n")
                print(List,"\n")

    return List
-- This will exclude files and traverse through 1 level of sub folders in the root

def list_files(dir):
    List = []
    filterstr = ' '
    for root, dirs, files in os.walk(dir, topdown = True):
        #r.append(root)
        if (root == dir):
            pass
        elif filterstr in root:
            #filterstr = ' '
            pass
        else:
            filterstr = root
            #print(root)
            for name in files:
                print(root)
                print(dirs)
                List.append(os.path.join(root,name))
            #print(os.path.join(root,name),"\n")
                print(List,"\n")

    return List