Python：遍历多个词典中的文件

Question

I have a number of files in a dictionary that I want to run a script on. Ordinarily, I would us 'os.listdir()' to list the files in my current working directory, and then tell my script to run on those files.

For instance:

dir = os.listdir():
for i in dir:
  do stuff

However, I want to run the script on these files when i am not in the current working directory. This will be so I can iterate through multiple folders later on. Any suggestions?

Answer 1

listdir() takes a path parameter. You could use something like this:

filelist1 = os.listdir("/home/user/directory1")
filelist2 = os.listdir("/home/user/directory2")

Answer 2

In order to read all files that are available under a directory:

from os import listdir
from os.path import isfile, join
onlyfiles = [f for f in listdir(mypath) if isfile(join(mypath, f))]

To list all available subdirs in a directory:

from os import listdir
from os.path import isdir, join

subdirs = [name for name in listdir(parent_dir) if isdir(join(parent_dir, name))]

Now let's combine those puzzles to list files only from sub-dirs of parent directory:

from os import listdir
from os.path import isfile, join, isdir

parent_dir = "/foo/bar"
dirs = [name for name in listdir(parent_dir) if isdir(join(parent_dir, name))]
onlyfiles = []

for dir in dirs:
    f = [f for f in listdir(dir) if isfile(join(dir, f))]
    onlyfiles += f

print(onlyfiles)

Example output:

$ python dummy.py 
['Dockerfile', 'docker-compose.yml', '53009790.py', 'MOCK_DATA.csv', '53021557.py', '53023079.py']
$ python3 dummy.py 
['Dockerfile', 'docker-compose.yml', '53009790.py', 'MOCK_DATA.csv', '53021557.py', '53023079.py']

You can also try use glob module, as it does pattern matching.

>>> import glob
>>> print(glob.glob('/home/rszamszur/*.sh'))
['/home/rszamszur/work-monitors.sh', '/home/rszamszur/default-monitor.sh', '/home/rszamszur/home-monitors.sh']

Key difference between OS module and glob is that OS will work for all systems, where glob only for Unix like.