Python语法与对象用法介绍

Python是一种高级编程语言，具有简单、易读、可扩展的特点。本文将从多个方面对Python的语法和对象进行详细阐述。

一、Python基础语法

1. 命名规则

# Python变量命名规则示例
firstName = "John"
last_name = "Doe"
age = 30

2. 数据类型

num = 10
pi = 3.14
name = "John Doe"
isTrue = True

3. 条件语句

# Python条件语句示例
if age >= 18:
    print("成年人")
else:
    print("未成年人")

二、Python函数

1. 定义函数

def add(num1, num2):
    return num1 + num2

sum = add(2, 3)
print(sum) # 输出 5

2. 默认参数

def greet(name, greeting="Hello"):
    print(greeting + ", " + name)

greet("John") # 输出 Hello, John
greet("Lisa", "Hi") # 输出 Hi, Lisa

3. 可变参数

def add(*nums):
    sum = 0
    for num in nums:
        sum += num
    return sum

total = add(1, 2, 3, 4)
print(total) # 输出 10

三、Python面向对象编程

1. 类与对象

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

    def say_hello(self):
        print("Hello, my name is " + self.name)

person1 = Person("John", 30)
person1.say_hello() # 输出 Hello, my name is John

2. 继承

class Employee(Person):
    def __init__(self, name, age, employee_id):
        super().__init__(name, age)
        self.employee_id = employee_id

    def get_employee_id(self):
        return self.employee_id

employee1 = Employee("Lisa", 25, "E12345")
employee1.say_hello() # 输出 Hello, my name is Lisa
print(employee1.get_employee_id()) # 输出 E12345

3. 多态

class Animal:
    def sound(self):
        pass

class Dog(Animal):
    def sound(self):
        print("Woof")

class Cat(Animal):
    def sound(self):
        print("Meow")

def make_sound(animal):
    animal.sound()

dog = Dog()
make_sound(dog) # 输出 Woof

cat = Cat()
make_sound(cat) # 输出 Meow

四、总结

本文对Python语法和对象进行了详细的阐述。通过了解Python的基础语法和函数，以及面向对象编程的概念，可以更好地运用Python进行开发。希望本文对你有所帮助！