Python: How to sort a list of dictionaries by several values?

I want to sort a list at first by a value and then by a second value. Is there an easy way to do this? Here is a small example:

    A = [{'name':'john','age':45},
         {'name':'andi','age':23},
         {'name':'john','age':22},
         {'name':'paul','age':35},
         {'name':'john','age':21}]

This command is for sorting this list by 'name':

    sorted(A, key = lambda user: user['name'])

But how I can sort this list by a second value? Like 'age' in this example.

I want a sorting like this (first sort by 'name' and then sort by 'age'):

    andi - 23
    john - 21
    john - 22
    john - 45
    paul - 35

Thanks!

    >>> A = [{'name':'john','age':45},
         {'name':'andi','age':23},
         {'name':'john','age':22},
         {'name':'paul','age':35},
         {'name':'john','age':21}]
    >>> sorted(A, key = lambda user: (user['name'], user['age']))
    [{'age': 23, 'name': 'andi'}, {'age': 21, 'name': 'john'}, {'age': 22, 'name': 'john'}, {'age': 45, 'name': 'john'}, {'age': 35, 'name': 'paul'}]

This sorts by a tuple of the two attributes, the following is equivalent and much faster/cleaner:

    >>> from operator import itemgetter
    >>> sorted(A, key=itemgetter('name', 'age'))
    [{'age': 23, 'name': 'andi'}, {'age': 21, 'name': 'john'}, {'age': 22, 'name': 'john'}, {'age': 45, 'name': 'john'}, {'age': 35, 'name': 'paul'}]

From the comments: @Bakuriu

I bet there is not a big difference between the two, but itemgetter avoids a bit of overhead because it extracts the keys and make the tuple during a single opcode(CALL_FUNCTION), while calling the lambda will have to call the function, load the various constants(which are other bytecodes) finally call the subscript (BINARY_SUBSCR), build the tuple and return it... that's a lot more work for the interpreter.

To summarize: itemgetter keeps the execution fully on the C level, so it's as fast as possible.

From: stackoverflow.com/q/16082954

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