Sorting by Multiple Fields in Python
Posted by Aly Sivji in Quick Hits
A couple of weeks ago, I stumbled across the Python Sorting HOW TO. Learned that Python can sort objects by multiple attributes using operator.attrgetter and operator.itemgetter.
In this Quick Hit, I will show the Pythonic way of sorting objects by multiple attributes.
Note: This example is leveraging Python 3.7 dataclasses for convenience. Objects can be of any type.
In [1]:
from dataclasses import dataclass
import operator
import random
import sys
from faker import Faker
fake = Faker()
In [2]:
sys.version_info
Out[2]:
In [3]:
# Create employees to sort
@dataclass(order=True)
class Employee:
name: str
age: int
title: str
employees = []
for idx in range(10):
_name = fake.name()
_title = fake.profile(fields="job")["job"]
_age = random.randint(18, 55)
employee = Employee(name=_name, title=_title, age=_age)
employees.append(employee)
In [4]:
employees
Out[4]:
In [5]:
sorted(employees)
Out[5]:
In [6]:
sorted(employees, key=operator.attrgetter("age"))
Out[6]:
In [7]:
sorted(employees, key=operator.attrgetter("age", "name"))
Out[7]:
Notice the employees are sorted by age and by name.
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