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@mikeckennedy
Last active June 30, 2021 06:30
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Add C# += / -= event subscriptions to Python using the Events package
from events import Events # Note you must pip install events
class Person:
def __init__(self, name: str, age: int, city: str):
self.__events = Events(('on_name_changed', 'on_age_changed', 'on_location_changed'))
self.on_name_changed = self.__events.on_name_changed
self.on_age_changed = self.__events.on_age_changed
self.on_location_changed = self.__events.on_location_changed
self.__name = name
self.__age = age
self.__city = city
@property
def age(self):
return self.__age
@age.setter
def age(self, value):
old = self.__age
self.__age = value
if old != value:
self.__events.on_age_changed(self)
@property
def name(self):
return self.__name
@name.setter
def name(self, value):
old = self.__name
self.__name = value
if old != value:
self.__events.on_name_changed(self)
@property
def city(self):
return self.__city
@city.setter
def city(self, value):
old = self.__city
self.__city = value
if old != value:
self.__events.on_location_changed(self)
def main():
p1 = Person("Michael", 47, "Portland")
p2 = Person("Zoe", 50, "Orlando")
p1.on_name_changed += lambda p: print(f"Person changed name to {p.name}.")
p1.on_location_changed += location_changed
p2.on_location_changed += location_changed
# Two moves for Zoe
p2.city = "Seattle"
p2.city = "LA"
# One move for Michael
p1.city = "Vancouver"
# One name change for Michael to Mike
p1.name = "Mike"
# No longer watching for moves for Michael
p1.on_location_changed -= location_changed
p1.city = "Portland"
def location_changed(person: Person):
print(f"Looks like {person.name} has moved to {person.city}")
if __name__ == '__main__':
main()
@mikeckennedy
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Here's the output I get when running locally:

Looks like Zoe has moved to Seattle
Looks like Zoe has moved to LA
Looks like Michael has moved to Vancouver
Person changed name to Mike.

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