I have a method that returns dynamic type based on the class I pass in:
def foo(cls):
return cls()
How can I setup typing for this function?
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1 Answer
After reading this article https://blog.yuo.be/2016/05/08/python-3-5-getting-to-grips-with-type-hints/, I found solution myself:
from typing import TypeVar, Type
class A:
def a(self):
return 'a'
class B(A):
def b(self):
return 'b'
T = TypeVar('T')
def foo(a: T) -> T:
return a()
This template suites my question above, but actually, my need is a little bit different that I need to work more. Below I include my problem and solution:
Problem: I want to use the with keyword like this:
with open_page(PageX) as page:
page.method_x() # method x is from PageX
Solution
from typing import TypeVar, Type, Generic
T = TypeVar('T')
def open_page(cls: Type[T]):
class __F__(Generic[T]):
def __init__(self, cls: Type[T]):
self._cls = cls
def __enter__(self) -> T:
return self._cls()
def __exit__(self, exc_type, exc_val, exc_tb):
pass
return __F__(cls)
So, when I use with PyCharm, it's able to suggest method_x when I pass PageX into with open_page(PageX) as page:
1 Comment
v0rtex20k
Fantastic solution, this worked perfectly for my use case