目录文件处理

>>> import os
>>> cwd = os.getcwd()
>>> cwd
'/home/dinsdale'

cwd stands for “current working directory”. The result in this example is /home/dinsdale, which is the home directory of a user named dinsdale.
A string like '/home/dinsdale' that identifies a file or directory is called a path.
A simple filename, like memo.txt is also considered a path, but it is a relative path because it relates to the current directory. If the current directory is /home/dinsdale, the filename memo.txt would refer to /home/dinsdale/memo.txt.
A path that begins with / does not depend on the current directory; it is called an absolute path. To find the absolute path to a file, you can use os.path.abspath:

>>> os.path.abspath('memo.txt')
'/home/dinsdale/memo.txt'

os.path provides other functions for working with filenames and paths. For example, os.path.exists checks whether a file or directory exists:

>>> os.path.exists('memo.txt')
True

If it exists, os.path.isdir checks whether it’s a directory:

>>> os.path.isdir('memo.txt')
False
>>> os.path.isdir('/home/dinsdale')
True

Similarly, os.path.isfile checks whether it’s a file.
os.listdir returns a list of the files (and other directories) in the given directory:

>>> os.listdir(cwd)
['music', 'photos', 'memo.txt']