Question

在我尝试定义一个n维Vector类时，我在定义乘法时遇到了'语法'错误，我真的不知道如何绕过......

class Vector:
def __init__(self, v):
    if len(v)==0: self.v = (0,0)
    else: self.v = v

 #bunch of functions in between here....

 def __mul__(self, other):
    if type(other) == Vector:
        if len(self.v) != len(other.v):
            raise AssertionError

    dotprod = 0
    for i in range(len(self.v)):
        dotprod += self.v[i+1] * other.v[i+1]
    return dotprod

elif type(other) in [int, float]:

    new = []
    for component in self.v:
        new.append(component*other)
    return Vector(tuple(new))
else:
    raise AssertionError

错误如下：

File "<ipython-input-52-50a37fd0919a>", line 40
elif type(other) in [int, float]:
   ^
SyntaxError: invalid syntax

我多次使用缩进和elif语句，我真的看不出是什么问题。

提前致谢。

Answer 1

问题肯定是缩进错误。我认为这就是你的意图：

def __mul__(self, other):
    if type(other) == Vector:
        if len(self.v) != len(other.v):
            raise AssertionError

        dotprod = 0
        for i in range(len(self.v)):
            dotprod += self.v[i+1] * other.v[i+1]
        return dotprod

    elif type(other) in [int, float]:

        new = []
        for component in self.v:
            new.append(component*other)
        return Vector(tuple(new))
    else:
        raise AssertionError

这会使elif与if处于同一缩进级别。

无法解释的语法错误

1 个答案: