Conditional import in a module

Question

I have created a module modA which I am importing in my main program. Depending on what happens in my main program (it has an interactive mode and a batch script mode), I want modA itself to import matplotlib with either the TkAgg backend or the ps backend. Is there a way for my main program to communicate information to modA to tell it how it should import matplotlib?

To clarify the situation:

The main program:

#if we are in interactive mode
#import modA which imports matplotlib using TkAgg backend
#else
#import modA which imports matplotlib using the ps backend

Module modA:

#import matplotlib
#matplotlib.use('ps') or matplotlib.use('TkAgg') (how can I do this?)

Answer 1

Have a function in your module which will determine this.

import matplotlib

def setEnv(env):
    matplotlib.use(env)

Then in your program you can have modA.setEnv('ps') or something else based on if-else statement condition.

You do not need a conditional import here (since you are using only one external module), but it is possible to do it:

if condition:
    import matplotlib as mlib
else:
    import modifiedmatplotlib as mlib

For more information about importing modules within function see these:

Python: how to make global imports from a function

Is it possible to import to the global scope from inside a function (Python)?