Python中elif语句的语法错误

Question

我在使用 Python 2.7 编写的这段代码时遇到了一些问题。它在 elif 语句上给了我一个语法错误，但是没有解释，我在代码中找不到任何合理的错误。 （typeline是我定义的一种方法。）

num = randrange(-25,15)
""" Toxic """
if num >= -25 and num < -10:
        responses = ["Ugh, nasty.", "That was absolutely disgusting.", "My stomach feels like it's going to explode.", "Pardon me if I puke."]
        typeline(responses[randrange(0,4)], "jack")
        return [num, "Jack ate a VERY TOXIC FRUIT and survived.", "Jack ate a VERY TOXIC FRUIT and died."]
""" Mildly poisonous """
elif num >= -10 and num < 0: """ SYNTAX ERROR HERE """
        responses = ["Yuck", "It's kinda bitter.", "Tastes like an unripe banana.", "It's not so bad."]
        typeline(responses[randrange(0,4)], "jack")
        return [num, "Jack ate a MILDLY TOXIC FRUIT and survived.", "Jack ate a MILDLY TOXIC FRUIT and died."]
""" Healthy """
else:
        responses = ["Definitely not too bad", "It's almost kind of tasty!", "Should I make a jam out of this?", "This is my new favorite fruit."]
        typeline(responses[randrange(0,4)], "jack")
        return [num, "Jack ate a HEALTHY FRUIT and was rescued.", "Jack ate HEALTHY FRUIT and survived."]

错误：

  File "<stdin>", line 9
    elif num >= -10 and num < 0:
       ^
SyntaxError: invalid syntax

Answer 1

elif 之前有一个未缩进的三引号字符串文字：

""" Mildly poisonous """
elif num >= -10 and num < 0:

"""...""" 字符串文字是不是多行 cmets。它们创建字符串，并且仅因为您随后忽略了生成的字符串对象，Python 才会忽略该行。它们仍然是 Python 语法的一部分；使用时不能忽略缩进规则。

改用正确的# cmets：

# Toxic
if num >= -25 and num < -10:
    # ...
# Mildly poisonous
elif num >= -10 and num < 0:
    # ...
# Healthy
else:
    # ...

由于语法完全忽略了 cmets，因此它们的缩进方式无关紧要。

如果您必须使用 """ ... """ 三引号字符串作为“块 cmets”，则必须将它们缩进以成为它们所在的 if 或 elif 块的一部分：

""" Toxic """
if num >= -25 and num < -10:
    # ...
    """ Mildly poisonous """
elif num >= -10 and num < 0:
    # ...
    """ Healthy """
else:
    # ...