Python函数提取文件路径的多个段

时间:2012-09-13 12:26:53

标签: python string filepath

我想编写一个能够获取文件路径的Python函数,例如:

  

/abs/path/to/my/file/file.txt

并返回三个字符串变量:

  • /abs - 根目录,以及路径中的“最顶层”目录
  • file - 路径中的“最底层”目录; file.txt
  • 的父级
  • path/to/my - 路径中最顶层和最底层目录之间的所有内容

所以使用以下伪代码:

def extract_path_segments(file):
    absPath = get_abs_path(file)
    top = substring(absPath, 0, str_post(absPath, "/", FIRST))
    bottom = substring(absPath, 0, str_post(absPath, "/", LAST))
    middle = str_diff(absPath, top, bottom)

    return (top, middle, bottom)

提前感谢您的帮助!

4 个答案:

答案 0 :(得分:5)

您正在寻找os.sep以及各种os.path模块功能。只需按该字符拆分路径,然后重新组合要使用的部件。类似的东西:

import os

def extract_path_segments(path, sep=os.sep):
    path, filename = os.path.split(os.path.abspath(path))
    bottom, rest = path[1:].split(sep, 1)
    bottom = sep + bottom
    middle, top = os.path.split(rest)
    return (bottom, middle, top)

处理Windows路径非常好,其中\ /都是合法的路径分隔符。在这种情况下,你有一个驱动器号,所以你也必须特殊情况。

输出:

>>> extract_path_segments('/abs/path/to/my/file/file.txt')
('/abs', 'path/to/my', 'file')

答案 1 :(得分:3)

使用os.path.split

import os.path

def split_path(path):
    """
    Returns a 2-tuple of the form `root, list_of_path_parts`
    """
    head,tail = os.path.split(path)
    out = []
    while tail:
        out.append(tail)
        head,tail = os.path.split(head)
    return head,list(reversed(out))

def get_parts(path):
    root,path_parts = split_path(path)
    head = os.path.join(root,path_parts[0])
    path_to = os.path.join(*path_parts[1:-2])
    parentdir = path_parts[-2]
    return head,path_to,parentdir

head,path_to,parentdir = get_parts('/foo/path/to/bar/baz')
print (head)        #foo
print (path_to)     #path/to
print (parentdir)   #bar

答案 2 :(得分:2)

我们应该使用os.path.split()os.path.join()

>>> import os
>>> pth = "/abs/path/to/my/file/file.txt"
>>> parts = []
>>> while True:
...     pth, last = os.path.split(pth)
...     if not last:
...         break
...     parts.append(last)
...
>>> pth + parts[-1]
'/abs'
>>> parts[1]
'file'
>>> os.path.join(*parts[-2:1:-1])
'path/to/my'

作为一项功能

import os

def extract_path_segments(pth):
    parts = []
    while True:
        pth, last = os.path.split(pth)
        if not last:
            break
        parts.append(last)
    return pth + parts[-1], parts[1], os.path.join(*parts[-2:1:-1])

答案 3 :(得分:1)

>>> p = '/abs/path/to/my/file/file.txt'
>>> r = p.split('/')
>>> r[1],'/'.join(r[2:-2]),r[-2]
('abs', 'path/to/my', 'file')