code: def camel_case(string):
      
      if not string:
          return string
      parts = snake_case(string).split('_')
      rv = ''
      while parts:
          part = parts.pop(0)
          rv += part or '_'
          if part:
              break
      return rv + ''.join(x.title() for x in parts)
docs: Converts a string to camel case. For example::
  
          camel_case('one_two_three') -> 'oneTwoThree'