How to programmatically set a global (module) variable?

python module global-variables
Eric O Lebigot picture Eric O Lebigot · Sep 15, 2009 · Viewed 21.7k times · Source

I would like to define globals in a "programmatic" way. Something similar to what I want to do would be:

definitions = {'a': 1, 'b': 2, 'c': 123.4}
for definition in definitions.items():
    exec("%s = %r" % definition)  # a = 1, etc.

Specifically, I want to create a module fundamentalconstants that contains variables that can be accessed as fundamentalconstants.electron_mass, etc., where all values are obtained through parsing a file (hence the need to do the assignments in a "programmatic" way).

Now, the exec solution above would work. But I am a little bit uneasy with it, because I'm afraid that exec is not the cleanest way to achieve the goal of setting module globals.

Answer

Nadia Alramli picture Nadia Alramli · Sep 16, 2009

Here is a better way to do it:

import sys
definitions = {'a': 1, 'b': 2, 'c': 123.4}
module = sys.modules[__name__]
for name, value in definitions.iteritems():
    setattr(module, name, value)

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