运算相关的魔法方法
思考:
class Person: def __init__(self,name,age): self.name = name self.age = age p1 = Person('zhangsan',18) p2 = Person('zhangsan',18) print(p1 == p2)
上述代码中，使用==运算符比较两个对象，结果是True还是False?==到底比较的是什么？
比较运算符相关魔法方法
class Student: def __init__(self, name, age): self.name = name self.age = age def __eq__(self, other): return self.name == other.name and self.age == other.age # def __ne__(self, other): def __lt__(self, other): return self.age < other.age # def __gt__(self, other): def __le__(self, other): return self.age <= other.age # def __ge__(self, other): s1 = Student('zhangsan', 18) s2 = Student('zhangsan', 18) s3 = Student('lisi', 20) print(s1 == s2) print(s1 != s2) print(s1 > s2) print(s1 >= s2) print(s1 <= s2) print(s1 <= s2)
算数运算符相关魔法方法
class Student: def __init__(self, name, age): self.name = name self.age = age def __add__(self, other): return self.age + other def __sub__(self, other): return self.age - other def __mul__(self, other): return self.age * other def __truediv__(self, other): return self.age / other def __mod__(self, other): return self.age % other def __pow__(self, power, modulo=None): return self.age ** power s = Student('zhangsan', 18) print(s + 1) # 19 print(s - 2) # 16 print(s * 2) # 36 print(s / 5) # 3.6 print(s % 5) # 3 print(s ** 2) # 324
类型转换相关魔法方法
class Student: def __init__(self, name, age): self.name = name self.age = age def __int__(self): return self.age def __float__(self): return self.age * 1.0 def __str__(self): return self.name def __bool__(self): return self.age > 18 s = Student('zhangsan', 18) print(int(s)) print(float(s)) print(str(s)) print(bool(s)) if s: print('hello')
