How to start an executable from a variable path

Question

I'm not able to start an executable from a variable path. I've tried:

os.system(destPath + '/BHC.exe')
os.system(destPath/BHC.exe)

the destPath is set correctly and the BHC.exe is in there.

How can I start the external program?

1) Do not use os.system but subprocess.call instead 2) Use os.path.join instead of manually joinining the file paths: import os, subprocess; subprocess.call([os.path.join(destPath, 'BHC.exe')]). — Bakuriu
– Bakuriu, Commented Nov 10, 2015 at 15:29
On Windows, os.system uses Windows components like cmd.exe which don't understand paths with forward slashes in them. Assuming destpath doesn't have any, try + '\\BHC.exe' (or better yet do as @Erica suggests). — martineau
– martineau, Commented Nov 10, 2015 at 15:54
@martineau os.system understands forward slashes for absolute paths but not relative paths. We'll know what's going on when OP finally answers @Undo's question. Why people post questions and then ignore requests for more information is the puzzling part! — tdelaney
– tdelaney, Commented Nov 10, 2015 at 16:42
Thanks for your information (and solution :-)! It works fine. — Vroluk
– Vroluk, Commented Nov 11, 2015 at 20:52

Community · Accepted Answer · 2017-05-23 12:23:39Z

1

Use os.path.join to avoid any slash confusion:

os.system(os.path.join(destPath, 'BHC.exe'))

If that doesn't resolve the problem, further troubleshooting is best answered by running an outside program (executable) in python?

CommunityBot

11 silver badge

answered Nov 10, 2015 at 15:30

Erica

2,4975 gold badges29 silver badges34 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

@tdelaney: But obviously doesn't, hence the question.

@martineau this answer Is extremely unlikely to fix the problem. Whatever causes OPs problem will still fail.mIt should be a comment.

@Erica Thank you! The os.path.join did the right thing :)