How to modify class object parameters in code

Question

What I'd like to accomplish is to set testobj.alpha to .5 in the example below:

class test():
    def __init__(self):
        self.alpha = 0

d = {'alpha' : .5}
testobj = test()

for i in d:
    testobj.i = d[i] #creates a new class member called 'i' instead of setting alpha to .5

As the comment says, in the for loop, a new class member called i is created, rather than setting the existing alpha member to .5

vaultah · Accepted Answer · 2015-02-15 17:55:16Z

3

Use setattr to set attributes dynamically:

for i in d:
    setattr(testobj, i, d[i])

or update the internal attribute dictionary directly (vars will serve as a proxy for the __dict__ attribute):

vars(testobj).update(d) # No (explicit) loop

The latter approach will fail if an object doesn't have the __dict__ attribute (e.g. it was defined with the __slots__ attribute).

edited Feb 15, 2015 at 17:55

answered Feb 15, 2015 at 17:24

vaultah

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