input: Write a function to generate a Python dictionary that contains the count of the characters in a given string. The function should return the dictionary with key as character and value as its count. If the input string is empty, the function should return an empty dictionary.
  assert count_chars("Hello World")=={'H': 1, 'e': 1, 'l': 3, 'o': 2, ' ': 1, 'W': 1, 'r': 1, 'd': 1}
  assert count_chars("Python")=={'P': 1, 'y': 1, 't': 1, 'h': 1, 'o': 1, 'n': 1}
  assert count_chars("")=={}
  assert count_chars("AaBbCc")=={'A': 1, 'a': 1, 'B': 1, 'b': 1, 'C': 1, 'c': 1}
  assert count_chars("12345")=={'1': 1, '2': 1, '3': 1, '4': 1, '5': 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