input: Write a python function to count the frequency of elements in a list.
  assert count_frequency(['a', 'a', 'b', 'a', 'c', 'a']) == {'a': 4, 'b': 1, 'c': 1}
  assert count_frequency([1, 2, 2, 3, 3, 3, 4, 4, 4, 4]) == {1: 1, 2: 2, 3: 3, 4: 4}
  assert count_frequency(['apple', 'banana', 'apple', 'apple', 'banana', 'cherry']) == {'apple': 3, 'banana': 2, 'cherry': 1}
output: def count_frequency(lst):
      frequency = {}
      for item in lst:
          if item in frequency:
              frequency[item] += 1
          else:
              frequency[item] = 1
      return frequency