How to change a variable by its name in Python?

Question

I can change a variable by it's name using globals():

k = 2 
def intercommunicationstep(xname, value):
    globals()[xname]=value
    return 1 - q**(k-1)

q = 0.2  
print(intercommunicationstep('k',1))

but for some reason the code is not working with locals() or vars():

def intercommunicationstep(xname, value):
    k = 2
    locals()[xname]=value
    print(locals())
    return 1 - q**(k-1)

q = 0.2 
print(intercommunicationstep('k',1))

it outputs 0.8 instead of 1. I don't want to bother global variables, and prefer to handle this inside function, but alas, I cannot figure this out.

what are you even trying to achieve by doing this? wouldn't `k = intercommunicationstep(k, 1)` work? — Sayse, Jul 26 '19 at 12:34
Possible duplicate of [Dynamically set local variable](https://stackoverflow.com/questions/8028708/dynamically-set-local-variable) — Error - Syntactical Remorse, Jul 26 '19 at 17:31

score 1 · Answer 1 · answered Jul 26 '19 at 12:36

1

It does not look like it's possible for optimization reasons : Any way to modify locals dictionary?.

If you absolutely need to have access to variables by key, you should probably create a dictionary inside of your function instead.

answered Jul 26 '19 at 12:36

Axnyff

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How to change a variable by its name in Python?

1 Answers1