否定python

Question

有没有办法否定一个函数，所以它返回负数。在我的功能中，我有条件，每个都有这个＆＃34; turtle＆＃34;移动。有没有办法否定这一点，所以每次乌龟移动都是消极的。我说的是＆＃39; =＆＃39;条件。

def ttInterpret( program ):
            """
            interpret program as a TinyTurtle language string.
            program -- a TinyTurtle string, possibly with string manipulation symbols
            """
            stor_pos = turtle.pos()
            spec_index = 0
            for ch in program:
                if ch >= '0' and ch <= '9':
                    turtle.fd(int(ch) * 10)
                elif ch == '<':
                    turtle.left(15)
                elif ch == 'L':
                    turtle.left(90)
                elif ch == '>':
                    turtle.right(15)
                elif ch == 'R':
                    turtle.right(90)
                elif ch == ' ':
                    pass

                elif ch == '@':
                    # ttInterpret( program[:program.index(ch):-1] )
                    stor_pos = turtle.pos() #keeps track of when @ was used
                    spec_index = program.index( ch ) #returns the index of the most recent specified character

                elif ch == '/':
                    fds_index = program.index( ch ) #returns last '/' index
                    ttInterpret( program[spec_index:fds_index - 1] )
                    # while ch != '/':
                        # ttInterpret( -program[ch::-1] )
                elif ch == '!':
                    turtle.setpos(stor_pos)

                elif ch == '=':
                    ttInterpret( program[:int(program.index(ch)):-1] ) #returns to start
                    ttInterpret( program[:int(program.index(ch)):1] ) #mirrors from start

                else:
                    print("Error: ", ch," is not supported by TinyTurtle")
            return

Answer 1

将整个代码放在while循环中，如下所示。

 while True:

然后，不要递归地调用相同的函数，而是使用：

program = program[:int(program.index(ch)):-1] 
continue #returns to start

和类似的

Answer 2

我最终只是复制了这个功能并否定了它中的所有内容。谢谢你们