CODEWITHSUNDEEP
pythonvariablesimportiteration
user3475234
user3475234

Reputation: 1573

python - iterate over various imports

If I do something like

import my_import
from my_import import *

I can change variables in the import by doing something like

my_import.k = 6

If I wanted to change the value of k for every single import I used, is there a way for me to iterate over all imports and set the value of k in each?

Essentially I'm looking for something like

for each x in [list of imports]
    x.k = 6

Upvotes: 0

Views: 6323

Answers (2)

streethacker
streethacker

Reputation: 328

If you just wanna change the attribute value of the imported module objects, you may try this code using function __import__() and map():

#__import__() & map()

In [1]: moduleNames = ['my_import1', 'my_import2', 'my_import3']

In [2]: for module in map(__import__, moduleNames):
   ...:     module.k = 1000
   ...:

And you can check the result by import this modules one by one, and output the k:

In [3]: import my_import1, my_import2, my_import3

In [4]: print my_import1.k
1000

In [5]: print my_import2.k
1000

In [6]: print my_import3.k
1000

Actually, you can change the map() function into a List Comprehension or a Generator, and the code would be much resemble your demanding code-style:

#List Comprehension

In [7]: for module in [__import__(m) for m in moduleNames]:
   ...:     module.k = 2000
   ...:     

In [8]: print my_import1.k
2000

In [9]: print my_import2.k
2000

In [10]: print my_import3.k
2000

In [11]: 

#Generator

In [11]: for module in (__import__(m) for m in moduleNames):
   ....:     module.k = 3000
   ....:     

In [12]: print my_import1.k
3000

In [13]: print my_import2.k
3000

In [14]: print my_import3.k
3000

In [15]:

BTW, the list comprehension and generator are quite similar, though. Generator is much more recommended when you have a large number of modules to deal with and no need to import them all at one time. It's more efficient and memory-saving.

Upvotes: 1

Eugene K
Eugene K

Reputation: 3457

There's some reasons to want this, but it's a dangerous game.

import my_import1
import my_import2
import my_import3
import sys

# Check if you don't believe me
print(my_import1.x)
print(my_import2.x)
print(my_import3.x)

# Grab the interesection of all loaded modules and globals in this scope
allmodules = [sys.modules[name] for name in set(sys.modules)&set(globals())]

for module in allmodules:
    module.x = 10000

# Check if you don't believe me
print(my_import1.x)
print(my_import2.x)
print(my_import3.x)

Output: 

1
2
3
10000
10000
10000

The caveat with this is that it will grab 'sys' as well and alter it. Perhaps add a check for "built-in" in the module key name.

Upvotes: 2

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