Converts a Python 2 function as
      lambda (x,y): x + y
    In the Python 3 format:
      lambda x,y : x + y

def lambda_tuple_converter(func):
    """
    Converts a Python 2 function as
      lambda (x,y): x + y
    In the Python 3 format:
      lambda x,y : x + y
    """
    if func is not None and func.__code__.co_argcount == 1:
        return lambda *args: func(args[0] if len(args) == 1 else args)
    else:
        return func