CODEWITHSUNDEEP
pythonglobal-variables
Derek
Derek

Reputation: 809

Proper Python Global Variable Use

I believe I have some fundamental misunderstanding of Python global variables and their scope, and I was hoping someone can educate me. Say I have two Python files.

#"GlobalSet.py"

global myVar
myVar = True

print "myVar" in globals()

import GlobalCheck

and 

#"GlobalCheck.py"

print "myVar" in globals()

Running "GlobalSet.py" surprisingly results in

True
False

Why isn't "myVar" in the global scope within "GlobalCheck"?

Upvotes: 0

Views: 398

Answers (2)

Daniel Roseman
Daniel Roseman

Reputation: 599630

Global in Python means global to the current module. To share variables between modules you need to import them.

Note that the global keyword in your code is doing nothing at all, since myVar is already defined at module level. You would only need to use that keyword if you were modifying the value of myVar inside a function in that module.

Upvotes: 2

user3757614
user3757614

Reputation: 1806

The global is within the context of the module. In GlobalCheck.py, if you put

import GlobalSet
print GlobalSet.myVar

that will work. (globals() doesn't appear to work across modules.)

Upvotes: 2

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