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Python implements sorting of custom class objects (using attrgetter)
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- 2018-10-20 14:50:032420browse
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1. Requirements
Sort the list of custom classes.2. Solution
The built-in sorted() function can accept a parameter key used to pass a callable object (callable), and the callable object will return to be Certain values in an object are sorted, and sorted uses these values to compare the objects.
Example:
from operator import attrgetter
class User:
def __init__(self,userId):
self.userId=userId
def __repr__(self):
return 'User({})'.format(self.userId)
users=[User(40),User(20),User(30)]
print(users)
#方法1
print(sorted(users,key=lambda u:u.userId))
#方法2
print(sorted(users,key=attrgetter('userId')))
Running result:
[User(40), User(20), User(30)] [User(20), User(30), User(40)] [User(20), User(30), User(40)]
attrgetter is usually a little faster. The above counting also applies to the min() and max() functions.
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