Import Script from a Parent Directory

Question

How do I import a module(python file) that resides in the parent directory?

Both directories have a __init__.py file in them but I still cannot import a file from the parent directory?

In this folder layout, Script B is attempting to import Script A:

Folder A:
   __init__.py
   Script A:
   Folder B:
     __init__.py
     Script B(attempting to import Script A)

The following code in Script B doesn't work:

import ../scriptA.py # I get a compile error saying the "." is invalid

Not exactly answering your question, but if you run __init__.py inside Folder A and try and import Folder B or Script B, Script A will be successfully imported inside Script B. — Michael0x2a, Jan 21 '12 at 07:01
Possible duplicate of [Importing modules from parent folder](https://stackoverflow.com/questions/714063/importing-modules-from-parent-folder) — Kaibo, Nov 01 '19 at 12:54

score 84 · Accepted Answer · answered Jan 21 '12 at 08:04

84

You don't import scripts in Python you import modules. Some python modules are also scripts that you can run directly (they do some useful work at a module-level).

In general it is preferable to use absolute imports rather than relative imports.

toplevel_package/
├── __init__.py
├── moduleA.py
└── subpackage
    ├── __init__.py
    └── moduleB.py

In moduleB:

from toplevel_package import moduleA

If you'd like to run moduleB.py as a script then make sure that parent directory for toplevel_package is in your sys.path.

answered Jan 21 '12 at 08:04

jfs

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And why shouldn't sys path "hacks" be used in this case? Python makes it so hard to do what you want here without them. What exactly is the downside here? – B T Oct 16 '12 at 00:05
4

@BT *«`sys.path.append(path_to_parent)`»* shouldn't be an answer to how to fix *«"import ../scriptA.py # I get a compile error saying the "." is invalid"»* question. There are cases where changing `sys.path` could be useful e.g., if python itself'd done it or a 3-party module that handles all corner cases correctly done it e.g., `import autopath; autopath.add_toplevel_to_syspath()` that automatically adds parent directory of toplevel_package to `sys.path` to allow a direct internal module execution as a script (or in a REPL) from any directory without proper PYTHONPATH or (virtualenv) install. – jfs Oct 16 '12 at 21:02
3

@J.F.Sebastian Is there some kind of proposal for a feature that allows us to explicit say what is the main folder or package of the whole project so that we don't have to care about adding parent directories to `sys.path` so that we can run submodules also as main files or scripts? I have a project where I really need to run scripts both as main or as modules, that is imported, but I need to do tons of hacks adding paths to `sys.path` to make them work in both cases. Would work in a virtualenv or using setuptools work somehow? I am really struggling with this... – nbro Feb 04 '16 at 23:23
2

@nbro the feature is called `pip install main-package`. You can run "submodules" already (just use their absolute names e.g., `python -ma.b.c`). If it is unclear; [ask](http://stackoverflow.com/questions/ask) – jfs Feb 04 '16 at 23:51
1

@jfs So what you are suggesting is to add toplevel_package to PYTHONPATH whenever I start to work on new application? – Xyz Dec 18 '17 at 12:36
@Pietrko: The answer discusses how to import `toplevel_package.moduleA` from `toplevel_package.subpackage.moduleB` that is run as a script. I don't see what it has to do with "new applications" – jfs Dec 18 '17 at 13:12
1

"If you'd like to run moduleB.py as a script then make sure that parent directory for toplevel_package is in your sys.path." This sentence is gold. That solved all my problems, thank you. – Géry Ogam Dec 22 '17 at 08:30
23

This solution doesn't work for me. It raises: "ImportError: No module named toplevel_package" – smart May 05 '18 at 08:03
This solution works on my local fine but when I build it on docker it throws error. Instead of that I coppied the file to the other location too. Idk if you had error while deploying on docker but this is just a warning note in case you have the same problem – alkanschtein Jul 01 '19 at 14:01
1

What if `moduleA.py` is in a folder? – David G Mar 06 '22 at 16:43

Rob Wouters · Answer 2 · 2012-01-21T07:09:31.450

37

From the docs:

from .. import scriptA

You can do this in packages, but not in scripts you run directly. From the link above:

Note that both explicit and implicit relative imports are based on the name of the current module. Since the name of the main module is always "__main__", modules intended for use as the main module of a Python application should always use absolute imports.

If you create a script that imports A.B.B, you won't receive the ValueError.

edited Jan 21 '12 at 07:09

answered Jan 21 '12 at 06:50

Rob Wouters

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ValueError: Attempted relative import in non-package – jgritty Jan 21 '12 at 06:57
3

@jgritty, that's because you're doing it in a script that you're running directly. – Rob Wouters Jan 21 '12 at 07:12
2

Yes, you're right. It will work if you call a script that then imports Script B. – jgritty Jan 21 '12 at 07:23
10

@jgritty `sys.path.append("..")` is what you're looking for – Feb 02 '18 at 09:21
8

Finally, 6 years later, the code snippet I've been looking for! – jgritty Feb 02 '18 at 17:38
1

@jgritty: "For every problem there is a solution that is simple, neat—and wrong." Mangling `sys.path` inside your script is the kind of solution that you grow to regret in time. – jfs Apr 12 '21 at 18:51

score 6 · Answer 3 · edited Apr 28 '17 at 21:44

6

If you want to run the script directly, you can:

Add the FolderA's path to the environment variable (PYTHONPATH).
Add the path to sys.path in the your script.

Then:

import module_you_wanted

edited Apr 28 '17 at 21:44

kenorb

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answered Jan 21 '12 at 07:46

capfredf

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score 0 · Answer 4 · answered Mar 11 '23 at 01:38

I struggled same kind of issue, and published syspend module on PyPI https://pypi.org/project/syspend/ This searches parent directories which have specific named file, and calls sys.path.append(directory: which has SYSPEND_ROOT file).

Folder A:
   __init__.py
   Script A:
   Folder B:
     __init__.py
     Script B(attempting to import Script A)
   SYSPEND_ROOT

In your case, please put SYSPEND_ROOT file. Empty file is OK. In your ScriptB.py

import syspend
import ScriptA

if __name__ == "__main__":
    ScriptA.method()

Import Script from a Parent Directory

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