PYTHONPATH variable blank

Question

According to documentation, sys.path is initialized from PYTHONPATH when a Python interpreter session starts. However, in my case, PYTHONPATH variable is empty. When I execute this in a terminal:

echo $PYTHONPATH

it returns blank. On the other hand, when I start the Python REPL and inspect sys.path:

import sys
print (sys.path)

I get back a long list of paths. Where do those get loaded from? What am I missing?

PYTHONPATH is usually undefined or empty

Ned Batchelder
– Ned Batchelder

2018-02-03 17:41:24 +00:00
Commented Feb 3, 2018 at 17:41 — Ned Batchelder
– Ned Batchelder, Commented Feb 3, 2018 at 17:41

Konrad Rudolph · Accepted Answer · 2018-02-03 16:30:19Z

6

Check the documentation again:

It says

[sys.path is initialized] from the environment variable PYTHONPATH, plus an installation-dependent default.

And furthermore,

the first item of this list, path[0], is the directory containing the script that was used to invoke the Python interpreter [… or] the empty string

That’s why yours isn’t empty.

edited Feb 3, 2018 at 16:30

answered Feb 3, 2018 at 16:28

Konrad Rudolph

549k142 gold badges967 silver badges1.3k bronze badges

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

3 Comments

idjaw Over a year ago

Also, some added explanation here on what PYTHONPATH is and when to use it. It is up to you to set what you want in that env var for additional paths you might want to use.

Matej Over a year ago

Thanks. Can you elaborate on installation-dependent defaults?

Konrad Rudolph Over a year ago

@Matej Not really: I don’t know exactly where they are configured but most of them are probably hard-coded into the Python configuration during compilation/installation. When installing Python from source you can configure its “prefix” path. That value, in conjunction with relative library path locations, is used to populate sys.path.

Collectives™ on Stack Overflow

PYTHONPATH variable blank

1 Answer 1

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related