CODEWITHSUNDEEP
pythonsubprocess
Florida Man
Florida Man

Reputation: 2147

subprocess cannot find folder

I simply want to execute some subprocesses form Python. As an example, I just change the directory with cd but it does not seem to work:

import subprocess
from pathlib import Path

subprocess.run('cd ' + str(Path.cwd()) + '/h5_to_pb/', capture_output=True)
...

Throws error :

FileNotFoundError: [Errno 2] No such file or directory: 'cd /home/base/Documents/Git/Projekte/CelebFaceMatcher/h5_to_pb/h5_to_pb/': 'cd /home/base/Documents/Git/Projekte/CelebFaceMatcher/h5_to_pb/h5_to_pb/'

When using the same command in the terminal, it works just fine. (Same error type is thrown with the actual command I want to run). What do I overlook? Thanks

Edit:

Thanks to Sven, I also tried following:

prog = subprocess.Popen('cd ' + str(Path.cwd()) + '/h5_to_pb/', stdout=subprocess.PIPE, stderr=subprocess.PIPE)
prog.communicate()  
if prog.returncode:
    raise Exception('program returned error code {0}'.format(prog.returncode))

Unfortunately with the same result.

Upvotes: 1

Views: 819

Answers (1)

Stanislav Ivanov
Stanislav Ivanov

Reputation: 1974

cd is not a program, it is a shell command (command for bash or sh or even cmd.exe). You can't call such commands directly, but you can run shell with such commands as argument:

import subprocess
from pathlib import Path

subprocess.run(['bash','-c', 'cd ' + str(Path.cwd()) + '/h5_to_pb/'], capture_output=True)

Where bash is a shell, -c — execute next argument as command, and 'cd ' + str(Path.cwd()) + '/h5_to_pb/' is a command.

Despite capture_output parameter this run output of this call is nothing, because cd prints nothing. You can make also a several commands in one shell call (and getting output):

subprocess.run(['bash','-c', 'cd ' + str(Path.cwd()) + '/h5_to_pb/ ; ls'], capture_output=True)

If you need run some program in different working directory — use cwd argument of run method.

Upvotes: 4

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