How to Sort a List of Dictionaries by a key in Python

Problem –

You have a list of dictionaries and you want to sort it based on a key in the dictionary.

Solution –

Let’s say we have a list of dictionary of stock prices and we want to sort it by stock name or price or may be both.

In [1]: prices = [{'name':'icici','price':712},
   ...:         {'name':'itc','price':245},
   ...:         {'name':'reliance','price':2463},
   ...:         {'name':'airtel','price':707}]

The sorting can be easily done using operator module’s itemgetter function.

In [2]: from operator import itemgetter

In [3]: by_price = sorted(prices, key=itemgetter('price'))

In [4]: by_price
Out[4]: 
[{'name': 'itc', 'price': 245},
 {'name': 'airtel', 'price': 707},
 {'name': 'icici', 'price': 712},
 {'name': 'reliance', 'price': 2463}]

In [5]: by_name = sorted(prices, key=itemgetter('name'))

In [6]: by_name
Out[6]: 
[{'name': 'airtel', 'price': 707},
 {'name': 'icici', 'price': 712},
 {'name': 'itc', 'price': 245},
 {'name': 'reliance', 'price': 2463}]

You can also sort by multiple keys.

In [7]: by_name_price = sorted(prices, key=itemgetter('name','price'))

In [8]: by_name_price
Out[8]: 
[{'name': 'airtel', 'price': 707},
 {'name': 'icici', 'price': 712},
 {'name': 'itc', 'price': 245},
 {'name': 'reliance', 'price': 2463}]