Subprocess command not finding files using ls command?

Question

I am creating a program that will pull in a list of account numbers and then run an ls -lh command to find a file for each one. When I run my command on our Linux server without Python it pulls up the files no problem, but then when I do it through Python it says it can't find them.

import subprocess as sp
sp.call(['cd', input_dir])
for i, e in enumerate(piv_id_list):
    proc_out = sp.Popen(['ls', '-lh', '*CSV*APP*{0}.zip'.format(e)])
    proc_out_list.append(proc_out)
    print(proc_out)

Here is some sample output when I run the commands through the Python interpreter:

>>> ls: cannot access *CSV1000*APP*: No such file or directory

But through Linux the same command:

ls -lh *CSV*APP*

It returns the output like it should.

Answer 1

This is because the shell does the replacement of wildcards with existing files that match the pattern. For example, if you have a.txt and b.txt, then ls *.txt will be expanded from the shell to ls a.txt b.txt. With your command you actually ask for ls to return info about a file containing an asterisk in its filename. Use the following if you want to verify:

sp.Popen(['bash', '-c', 'ls', '-lh', '*CSV*APP*{0}.zip'.format(e)])

Also you should use os.chdir to change the directory, since sp.call(['cd', input_dir]) changes the current directory for the new process you created and not the parent one.