Fix Python – How do I call setattr() on the current module?

Question

Asked By – Matt Joiner

What do I pass as the first parameter “object” to the function setattr(object, name, value), to set variables on the current module?

For example:

setattr(object, "SOME_CONSTANT", 42);

giving the same effect as:

SOME_CONSTANT = 42

within the module containing these lines (with the correct object).

I’m generate several values at the module level dynamically, and as I can’t define __getattr__ at the module level, this is my fallback.

Now we will see solution for issue: How do I call setattr() on the current module?


Answer

import sys

thismodule = sys.modules[__name__]

setattr(thismodule, name, value)

or, without using setattr (which breaks the letter of the question but satisfies the same practical purposes;-):

globals()[name] = value

Note: at module scope, the latter is equivalent to:

vars()[name] = value

which is a bit more concise, but doesn’t work from within a function (vars() gives the variables of the scope it’s called at: the module’s variables when called at global scope, and then it’s OK to use it R/W, but the function’s variables when called in a function, and then it must be treated as R/O — the Python online docs can be a bit confusing about this specific distinction).

This question is answered By – Alex Martelli

This answer is collected from stackoverflow and reviewed by FixPython community admins, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0