Setting path in Python

Question

Is there a way to set the terminal path in Python? I have some compiled binaries that I'll like to use in a folder, let's just say foo.exe in C:/Program Files/PostgreSQL/9.2/bin, and I figured there had to be something in the os or sys modules that would work, but I couldn't find any:

# This works, but ugly
psqldir = 'C:/Program Files/PostgreSQL/9.2/bin'
currentdir = os.getcwd()
os.chdir(psqldir)
os.system('foo')
os.chdir(currentdir)
# Does not work
os.system('set PATH=%PATH%;C:/Program Files/PostgreSQL/9.2/bin')
os.system('foo')
# Does not work
sys.path.append('C:\\Program Files\\PostgreSQL\9円.2\\bin')
os.system('foo')

Thanks!

• glglgl: os.system()? Not good...
• elleciel: Ouch. Is there a better style? I'm open to suggestion.
• Aya: @ephedyn See the last sentence of kindall's answer.
• elleciel: @Aya I don't see any answer from a kindall, did something happen? Btw your answer does exactly what I was trying to do - thanks!
• glglgl: Alas, kindall has deleted their answer - whyever. So the answer is "Use the subprocess module".

Answer 1

Something like this should work...

import os
psqldir = 'C:/Program Files/PostgreSQL/9.2/bin'
os.environ['PATH'] = '%s;%s' % (os.environ['PATH'], psqldir)
os.system('foo')

...or just call foo.exe by its full path...

os.system('C:/Program Files/PostgreSQL/9.2/bin/foo')

However, as kindall's (now-deleted) answer suggested, it's worth noting this paragraph from the os.system() documentation...

The subprocess module provides more powerful facilities for spawning new processes and retrieving their results; using that module is preferable to using this function. See the Replacing Older Functions with the subprocess Module section in the subprocess documentation for some helpful recipes.

• glglgl: +1 for calling with full path, -0.4 for not recommending subprocess, makes +0.6, rounds to +1.
• Aya: @glglgl I thought it'd be rude to usurp kindall's suggestion of subprocess, but now he's deleted it, I'll add it in.

Answer 2

How I understand this is that you need to add an environment variable . I think you should be able to do that using os.system / os.environ or subprocess . Also considering that you are on windows you might want to check these articles

http://code.activestate.com/recipes/416087/

http://code.activestate.com/recipes/159462/

• elleciel: Thanks for the tips, will go through them.