I’m having trouble sorting a list of objects in Python. I have a list of Person objects, and I want to sort them based on their age. However, the sorting doesn’t seem to be working as expected. Here’s my code:
class Person:
def __init__(self, name, age):
self.name = name
self.age = age
people = [
Person("Alice", 30),
Person("Bob", 25),
Person("Charlie", 40),
Person("David", 22)
]
sorted_people = sorted(people, key=lambda person: person.age)
print(sorted_people)
I expected the output to be a list of Person objects sorted by their age, like this:
[Person("David", 22), Person("Bob", 25), Person("Alice", 30), Person("Charlie", 40)]
However, the actual output I’m getting is:
[<__main__.Person object at 0x...>, <__main__.Person object at 0x...>, ...]
It seems like the sorting is not working as intended. What am I doing wrong? How can I fix this sorting issue?
>Solution :
Add a __repr__ implementation to your class to get nice default string representations:
class Person:
def __init__(self, name, age):
self.name = name
self.age = age
def __repr__(self):
return f'Person({repr(self.name)}, {self.age})'
As Kelly Bundy points out, you can also use the !r shorthand in the f-string literal to call repr() on the member items:
class Person:
# ...
def __repr__(self):
return f'Person({self.name!r}, {self.age!r})'