Setting values persisting over python sessions

Question

I'd like to define a constant in my script like that path to my Dropbox folder. Most my scripts will try to load some data of Dropbox which is shared among my PCs, but I find that between Mac and Ubuntu the prefix is different (/Users/<user>/Dropbox versus /home/<user>/Dropbox).

Is there a way to save this kind of information in some variable that will be loaded in each session such that I could have a global variable like DROPBOX (what would be a good convention, __DROPBOX__?) as path prefix to a file name, e.g. fname = DROPBOX + "myfile.txt".

Kind of reminds of me defining this in one's .Rprofile which holds settings in R.

Or is there a better way to handle this?

See http://stackoverflow.com/questions/13887798/saving-and-recovering-values-of-variables-between-executions — user3757614, Oct 01 '14 at 21:11
@user3757614 Bad example, I know pickling certainly is not the way to go. — PascalVKooten, Oct 01 '14 at 21:13

score 2 · Answer 1 · answered Oct 01 '14 at 21:15

2

You could use the built in environment variables to get the path to the user home directory:

import os
print os.environ['HOME']

Which would solve your problem is a way that is more likely to remain stable if run on a new machine.

answered Oct 01 '14 at 21:15

Tom Anthony

791
7
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Excellent, knew there must have been something. – PascalVKooten Oct 01 '14 at 21:15
Then again, having to import os and use that long name is still not preferred. I guess I should just work with relative paths unfortunately. – PascalVKooten Oct 01 '14 at 21:18

m.wasowski · Answer 2 · 2014-10-01T22:14:44.673

0

How about this:

os.path.expanduser('~/Dropbox')

or you can just try different alternatives:

dirs_to_try = ('/Users/Guido/Dropbox', '/home/Guido/Dropbox')
for path in dirs_to_try:
    if os.path.isdir(path):
        break
finally:
    print 'cannot find Dropbox directory'
    path = None

edited Oct 01 '14 at 22:14

answered Oct 01 '14 at 22:08

m.wasowski

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1
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I mean... one way would be to make it a function globally, but then still I would basically want it to just be available in ANY python session, from the get-go. That's the problem in the first place. – PascalVKooten Oct 02 '14 at 07:38

Setting values persisting over python sessions

2 Answers2