I have two instances of Python class (i simplified logic to make it shorter)
class First:
def first_p(self):
print('test')
first_instance = First()
second_instance = First()
Now i need select which one instance to use (i could do it by repeat code in if/else)
if x:
second.first_p()
else:
first.first_p()
But i wander how i can do it like this (it's not working)
'{}'.first_p().format(second)
I think the question can be simplified into "How could I access a variable base on the string?"
It is actually possible, depends on the scope:
# global scope
instance = globals()[second]
instance.first_p()
Ref: https://www.programiz.com/python-programming/methods/built-in/globals
# local scope, such as inside a function
instance = locals()[second]
instance.first_p()
Ref: https://www.programiz.com/python-programming/methods/built-in/locals
I think you're trying to achieve something like this:
class First:
def first_p(self):
return 'test'
first_instance = First()
second_instance = First()
print(f"{ (first_instance if x else second_instance).first_p() }")
because "'{}'.first_p().format(second)" doesn't make any sense (since you're calling first_p as if it's a method in Str)
'{}'.format(second_instance.p() if x else first_instance.p())
dictthat maps the strings to the desired objects.