sort dictionary by value and key in python 3 code example

Example 1: how can I sort a dictionary in python according to its values?

s = {1: 1, 7: 2, 4: 2, 3: 1, 8: 1}
k = dict(sorted(s.items(),key=lambda x:x[0],reverse = True))
print(k)

Example 2: python sort dict by value

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

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