定义一个复数类，包括实部和虚部成员变量、构造方法、输出复数、以及两个复数的加法__add__( )、乘法__mul__( )和大于__gt__( )运算定义

好的，以下是可以回答的代码：

class Complex:
def __init__(self, realpart, imagpart):
self.realpart = realpart
self.imagpart = imagpart

def __str__(self):
return '{} + {}i'.format(self.realpart, self.imagpart)

def __add__(self, other):
return Complex(self.realpart + other.realpart, self.imagpart + other.imagpart)

def __mul__(self, other):
return Complex(self.realpart*other.realpart - self.imagpart*other.imagpart,
self.realpart*other.imagpart + self.imagpart*other.realpart)

def __gt__(self, other):
if self.realpart > other.realpart and self.imagpart > other.imagpart:
return True
else:
return False

# 调用
c1 = Complex(3, 4)
c2 = Complex(2, 3)
print(c1 + c2)
print(c1 * c2)
print(c1 > c2)