input: Write a function to generate a Python dictionary that contains the count of each character in a given string. The function should return the dictionary with each character as the key and the count as the value.
  assert count_chars("Hello World")=={'H': 1, 'e': 1, 'l': 3, 'o': 2, ' ': 1, 'W': 1, 'r': 1, 'd': 1}
  assert count_chars("Python Programming")=={'P': 2, 'y': 1, 't': 1, 'h': 1, 'o': 1, 'n': 3, ' ': 1, 'r': 1, 'g': 2, 'a': 1, 'm': 2, 'i': 1}
  assert count_chars("")=={}
  assert count_chars("aabbcc")=={'a': 2, 'b': 2, 'c': 2}
  assert count_chars("123ABCabc")=={'1': 1, '2': 1, '3': 1, 'A': 1, 'B': 1, 'C': 1, 'a': 1, 'b': 1, 'c': 1}
output: def count_chars(s):
      char_count = {}
      for char in s:
          if char in char_count:
              char_count[char] += 1
          else:
              char_count[char] = 1
      return char_count