Extract a part of the filepath (a directory) in Py

问题:

I need to extract the name of the parent directory of a certain path. This is what it looks like: c:\ stuff \ directory_i_need \ subdir \ file. I am modifying the content of the "file" with something that uses the directory_i_need name in it (not the path). I have created a function that will give me a list of all the files, and then...

for path in file_list:
   #directory_name = os.path.dirname(path)   # this is not what I need, that's why it is commented
   directories, files = path.split('\\')

   line_replace_add_directory = line_replace + directories  
   # this is what I want to add in the text, with the directory name at the end 
   # of the line.

How can I do that?

回答1:

import os
## first file in current dir (with full path)
file = os.path.join(os.getcwd(), os.listdir(os.getcwd())[0])
file
os.path.dirname(file) ## directory of file
os.path.dirname(os.path.dirname(file)) ## directory of directory of file
...

And you can continue doing this as many times as necessary...

Edit: from os.path, you can use either os.path.split or os.path.basename:

dir = os.path.dirname(os.path.dirname(file)) ## dir of dir of file
## once you're at the directory level you want, with the desired directory as the final path node:
dirname1 = os.path.basename(dir) 
dirname2 = os.path.split(dir)[1] ## if you look at the documentation, this is exactly what os.path.basename does.

回答2:

In Python 3.4 you can use the pathlib module:

>>> from pathlib import Path
>>> p = Path('C:\Program Files\Internet Explorer\iexplore.exe')
>>> p.name
'iexplore.exe'
>>> p.suffix
'.exe'
>>> p.root
'\\'
>>> p.parts
('C:\\', 'Program Files', 'Internet Explorer', 'iexplore.exe')
>>> p.relative_to('C:\Program Files')
WindowsPath('Internet Explorer/iexplore.exe')
>>> p.exists()
True

回答3:

First, see if you have splitunc() as an available function within os.path. The first item returned should be what you want... but I am on Linux and I do not have this function when I import os and try to use it.

Otherwise, one semi-ugly way that gets the job done is to use:

>>> pathname = "\\C:\\mystuff\\project\\file.py"
>>> pathname
'\\C:\\mystuff\\project\\file.py'
>>> print pathname
\C:\mystuff\project\file.py
>>> "\\".join(pathname.split('\\')[:-2])
'\\C:\\mystuff'
>>> "\\".join(pathname.split('\\')[:-1])
'\\C:\\mystuff\\project'

which shows retrieving the directory just above the file, and the directory just above that.

回答4:

This is what I did to extract the piece of the directory:

for path in file_list:
  directories = path.rsplit('\\')
  directories.reverse()
  line_replace_add_directory = line_replace+directories[2]

Thank you for your help.

回答5:

You have to put the entire path as a parameter to os.path.split. See The docs. It doesn't work like string split.