LeetCode Majority Element Python

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.

You may assume that the array is non-empty and the majority element always exist in the array.

 class Solution:
     # @param num, a list of integers
     # @return an integer
     def majorityElement(self, num):
         dic = {}
         for i in range(len(num)):
             if (num[i]) not in dic:
                 dic[num[i]] = 1
             else:
                 dic[num[i]] += 1
         l = [(a,b) for a, b in dic.items()]
         return (sorted(l,key = lambda x:x[1]))[-1][0]