python sort list by key code example

Example 1: python sort list in reverse

#1 Changes list
list.sort(reverse=True)
#2 Returns sorted list
sorted(list, reverse=True)

Example 2: python sort dict by key

A={1:2, -1:4, 4:-20}
{k:A[k] for k in sorted(A)}

output:
{-1: 4, 1: 2, 4: -20}

Example 3: python sort list

# sort() will change the original list into a sorted list
vowels = ['e', 'a', 'u', 'o', 'i']
vowels.sort()
# Output:
# ['a', 'e', 'i', 'o', 'u']

# sorted() will sort the list and return it while keeping the original
sortedVowels = sorted(vowels)
# Output:
# ['a', 'e', 'i', 'o', 'u']

Example 4: python sort

>>> student_tuples = [
...     ('john', 'A', 15),
...     ('jane', 'B', 12),
...     ('dave', 'B', 10),
... ]
>>> sorted(student_tuples, key=lambda student: student[2])   # sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

Example 5: list sort by key python

>>> student_tuples = [
...     ('john', 'A', 15),
...     ('jane', 'B', 12),
...     ('dave', 'B', 10),
... ]
>>> sorted(student_tuples, key=lambda student: student[2])   
# sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

Example 6: python sort dictionary by key

In [1]: import collections

In [2]: d = {2:3, 1:89, 4:5, 3:0}

In [3]: od = collections.OrderedDict(sorted(d.items()))

In [4]: od
Out[4]: OrderedDict([(1, 89), (2, 3), (3, 0), (4, 5)])