Python SyntaxError :'return' 外部函数

Question

编译器显示:

File "temp.py", line 56
    return result
SyntaxError: 'return' outside function

我哪里错了？

class Complex (object):
    def __init__(self, realPart, imagPart):
        self.realPart = realPart
        self.imagPart = imagPart            

    def __str__(self):
        if type(self.realPart) == int and type(self.imagPart) == int:
            if self.imagPart >=0:
                return '%d+%di'%(self.realPart, self.imagPart)
            elif self.imagPart <0:
                return '%d%di'%(self.realPart, self.imagPart)   
    else:
        if self.imagPart >=0:
                return '%f+%fi'%(self.realPart, self.imagPart)
            elif self.imagPart <0:
                return '%f%fi'%(self.realPart, self.imagPart)

        def __div__(self, other):
            r1 = self.realPart
            i1 = self.imagPart
            r2 = other.realPart
            i2 = other.imagPart
            resultR = float(float(r1*r2+i1*i2)/float(r2*r2+i2*i2))
            resultI = float(float(r2*i1-r1*i2)/float(r2*r2+i2*i2))
            result = Complex(resultR, resultI)
            return result

c1 = Complex(2,3)
c2 = Complex(1,4)
print c1/c2

这个呢？

class Complex (object):
    def __init__(self, realPart, imagPart):
        self.realPart = realPart
        self.imagPart = imagPart            

    def __str__(self):
        if type(self.realPart) == int and type(self.imagPart) == int:
            if self.imagPart >=0:
                return '%d+%di'%(self.realPart, self.imagPart)
            elif self.imagPart <0:
                return '%d%di'%(self.realPart, self.imagPart)
        else:
            if self.imagPart >=0:
                return '%f+%fi'%(self.realPart, self.imagPart)
            elif self.imagPart <0:
                return '%f%fi'%(self.realPart, self.imagPart)

    def __div__(self, other):
        r1 = self.realPart
        i1 = self.imagPart
        r2 = other.realPart
        i2 = other.imagPart
        resultR = float(float(r1*r2+i1*i2)/float(r2*r2+i2*i2))
        resultI = float(float(r2*i1-r1*i2)/float(r2*r2+i2*i2))
        result = Complex(resultR, resultI)
        return result

c1 = Complex(2,3)
c2 = Complex(1,4)
print c1/c2

Answer 1

我会检查我的缩进，它看起来不对。你可能混合制表符和空格吗？ PEP8 (Python Style Guide)建议使用 4 spaces only .与其他语言不同，白色空格在 Python 中有很大的不同，因此一致性很重要。

以上还提出以下建议:

When invoking the Python command line interpreter with the -t option, it issues warnings about code that illegally mixes tabs and spaces. When using -tt these warnings become errors. These options are highly recommended!

特别是，你的第二个 else 似乎关闭了(可能应该缩进)，这个方法 def __div__(self, other): 也是(我会think 应该与您的其他 def 处于同一级别 - 即“移出”而不是缩进)。

混合制表符/空格很容易出现问题，因为这两个字符都是“不可见的”。