1. isinstance, type, issubclass

isinstance: judge whether the object you give is of type xx

Type: returns the data type of xxx object

issubclass: a subclass to determine whether the xxx class is xxx

class Animal:
    def eat(self):
        print("Just woke up to eat something")

class Cat(Animal):
    def play(self):
        print("Cats like to play")

c = Cat()

print(isinstance(c, Cat)) # True
print(isinstance(c, Animal)) # True

a = Animal()
print(isinstance(a, Cat)) # Can't judge down  False

print(type(a)) # Return a Data type of
print(type(c)) # Precisely tell you the data type of this object

# judge.xx Is class A xxxx Subclasses of classes
print(issubclass(Cat, Animal))  # True
print(issubclass(Animal, Cat))  # False

2. How to distinguish methods and functions

In class:

Instance method

If it is a class name. Method function

If it is an object, method

Class method: all methods

Static methods: all functions

    from types import MethodType, FunctionType

    isinstance()

from types import FunctionType, MethodType  #  Modules introducing methods and functions
class Person:
    def chi(self): # Example method
        print("I want to eat fish.")

    @classmethod
    def he(cls):
        print("I'm a class method")

    @staticmethod
    def pi():
        print("You are the real skin")

p = Person()

print(isinstance(Person.chi, FunctionType)) # True
print(isinstance(p.chi, MethodType)) # True

print(isinstance(p.he, MethodType)) # True
print(isinstance(Person.he, MethodType)) # True

print(isinstance(p.pi, FunctionType)) # True
print(isinstance(Person.pi, FunctionType)) # True

3. reflection

There are four functions

    attr: attribute

    getattr()

Get xxx property value from xxx object

    hasattr()

Determine whether xxx property value exists in xxx object

    delattr()

Remove xxx property from xxx object

    setattr()

Set xxx property in xxx object to xxxx value

class Person:
    def __init__(self, name,wife):
        self.name = name
        self.wife = wife


p = Person("baby", "Lin Chiling")

print(hasattr(p, "wife")) 
print(getattr(p, "wife")) # p.wife

setattr(p, "wife", "Hu Yi Fei") # p.wife = Hu Yi Fei
setattr(p, "money", 100000) # p.money = 100000

print(p.wife)
print(p.money)

delattr(p, "wife") # Put the xxx Attribute Removal. Not at all p.wife = None
print(p.wife)