How to get a reference to a module inside the module itself?

Question

How can I get a reference to a module from within that module? Also, how can I get a reference to the package containing that module?

Refund

I suspect you might be asking this question because you have a variable in module scope (e.g., BLAH=10 outside a function or class), then a class/function variable named BLAH, and you want to differentiate. A valid question here is: Is this necessary? Scope rules are notoriously prone to mistake, especially by the 'idiot' who picks up your code after you (i.e., you, 6 months later). Tricks like this are rarely necessary; I attempt to avoid them completely because they're so often confusing and wrongly modified later. – Toll

@KevinJ.Rice "the 'idiot' who picks up your code after you (i.e., you, 6 months later)" made my day! – Standpipe

Who cares why he is asking the question? There are plenty of valid reasons to need to do this. – Athanor

@Christopher: Although the need doesn't often arise, here's a case in point. – Tales

Answer 1

import sys
current_module = sys.modules[__name__]

Nessus

except for this won't be quite correct if module is reloaded; I don't think there's any place where a reference is guaranteed to be kept, if there was, reloading wouldn't really work, right? – Babushka

Reloading re-uses the same module object; no new module object is created, so it's still correct in the face of re-loading. – Galangal

tks, only this answer works directly with module path with dots – Shererd

Answer 2

One more technique, which doesn't import the sys module, and arguably - depends on your taste - simpler:

current_module = __import__(__name__)

Be aware there is no import. Python imports each module only once.

Finagle

This seems like a really nice way to avoid importing sys. Other than being a bit counter-intuitive to read are there any potential downsides to this approach? – Defector

@JeremyDouglass. Not that I'm aware of. import is a legit, documented, built-in function (the only xx function). You can replace it with the 'importlib' package (you'll have to import it). Maybe - never happened to me - you could have an issue with relative/absolute import, if a module with the same name is available in sys.path, in which case you can solve it with the 'level' argument of the function. – Finagle

This solution does not work on my code. Instead of create a reference to the module, it creates a reference to the package. Am I the only one to have this behavior ? – Silveira

@Silveira - I too am seeing this behavior (getting a reference to the package instead of the module) on Python 3.9 – Pathology

Per the docstring: "When importing a module from a package, note that __import__('A.B', ...) returns package A when fromlist is empty, but its submodule B when fromlist is not empty." It is also advised in the same place to use importlib.import_module instead, which does not have this behavior. – Mccammon

Do not use this answer, it will drive you nuts with unintuitive behavior like sometimes importing a higher up module than the one you specified. Details: https://mcmap.net/q/128799/-how-to-use-the-__import__-function-to-import-a-name-from-a-submodule – Whaleback

Answer 3

If you have a class in that module, then the __module__ property of the class is the module name of the class. Thus you can access the module via sys.modules[klass.__module__]. This is also works for functions.

Obie

Answer 4

You can get the name of the current module using __name__

The module reference can be found in the sys.modules dictionary.

See the Python documentation

Tweeze

Answer 5

According to @truppo's answer and this answer (and PEP366):

Reference to "this" module:

import sys
this_mod = sys.modules[__name__]

Reference to "this" package:

import sys
this_pkg = sys.modules[__package__]

__package__ and __name__ are the same if from a (top) __init__.py

Eubank

Answer 6

You can pass it in from outside:

mymod.init(mymod)

Not ideal but it works for my current use-case.

Creeper

Answer 7

If all you need is to get access to module variable then use globals()['bzz'] (or vars()['bzz'] if it's module level).

Chickamauga

Answer 8

from importlib import import_module
current_module = import_module(__name__)

PS: see also Sargera's comment

Ayotte