Introduction

Hello, students! Today we will learn about operators in Python. An operator is a symbol that tells the computer to perform specific operations (操作). Understanding operators is essential (必要的) for writing Python programs. Let’s start with the most common ones!

1. Arithmetic Operators (算术运算符)

These operators are used for math calculations.

Code Example:

a = 10  
b = 3  
print(a + b)   # Output: 13  
print(a * b)   # Output: 30  
print(a ** b)  # Output: 1000 (10×10×10)  

2. Assignment Operators (赋值运算符)

These operators are used to assign values to variables.

Code Example:

x = 5  
x += 2   # Now x is 7  
x *= 3   # Now x is 21  
print(x) # Output: 21  

3. Comparison Operators (比较运算符)

These operators compare values and return True or False.

Code Example:

a = 8  
b = 8  
print(a == b)  # Output: True  
print(a != b)  # Output: False  
print(a >= 10) # Output: False  

4. Logical Operators (逻辑运算符)

These operators combine conditional (条件的) statements.

Code Example:

age = 18  
has_ticket = True  
if age >= 18 and has_ticket:  
    print("Can enter.")  # Output: Can enter.  
else:  
    print("Cannot enter.")  

5. Membership Operators (成员运算符)

These operators check if a value exists in a sequence (序列, like a list or string).

Code Example:

fruits = ["apple", "banana"]  
print("apple" in fruits)   # Output: True  
print("orange" not in fruits) # Output: True  

6. Identity Operators (身份运算符)

These operators check if two variables refer to the same object.

Code Example:

x = [1, 2, 3]  
y = x  
print(x is y)  # Output: True (same object)  
z = [1, 2, 3]  
print(x is z)  # Output: False (different objects)  

Conclusion

Operators are the building blocks (基石) of Python programming! Practice using them in simple programs to get familiar.

轻松学 Python 运算符：学生初学者指南

引言

同学们好！今天我们将学习Python中的运算符（operator）。运算符是告诉计算机执行特定操作的符号。理解运算符是编写Python程序的必要技能。让我们从最常见的开始吧！

1. 算术运算符

这些运算符用于数学计算。

代码示例：

a = 10  
b = 3  
print(a + b)   # 输出：13  
print(a * b)   # 输出：30  
print(a ** b)  # 输出：1000（10×10×10）  

2. 赋值运算符

这些运算符用于为变量赋值。

代码示例：

x = 5  
x += 2   # 现在x是7  
x *= 3   # 现在x是21  
print(x) # 输出：21  

3. 比较运算符

这些运算符用于比较值，返回True或False。

代码示例：

a = 8  
b = 8  
print(a == b)  # 输出：True  
print(a != b)  # 输出：False  
print(a >= 10) # 输出：False  

4. 逻辑运算符

这些运算符用于组合条件语句。

代码示例：

年龄 = 18  
有票 = True  
if 年龄 >= 18 and 有票:  
    print("可以进入。")  # 输出：可以进入。  
else:  
    print("不能进入。")  

5. 成员运算符

这些运算符用于检查值是否存在于序列中（如列表或字符串）。

代码示例：

水果 = ["苹果", "香蕉"]  
print("苹果" in 水果)   # 输出：True  
print("橙子" not in 水果) # 输出：True  

6. 身份运算符

这些运算符用于检查两个变量是否引用同一个对象。

代码示例：

x = [1, 2, 3]  
y = x  
print(x is y)  # 输出：True（同一个对象）  
z = [1, 2, 3]  
print(x is z)  # 输出：False（不同对象）  

结论

运算符是Python编程的基石！通过在简单程序中练习使用它们来熟悉。

专业词汇及不常用词汇表

1. operator, /'pret(r)/, n，运算符
2. essential, /'senl/, adj，必要的
3. arithmetic, /'rθmtk/, adj，算术的
4. modulus, /'mdjls/, n，取余
5. floor division, /fl(r)/ /d'vn/, n，整除
6. exponent, /k'spnnt/, n，指数
7. assignment, /'sanmnt/, n，赋值
8. comparison, /km'paersn/, n，比较
9. logical, /'ldkl/, adj，逻辑的
10. conditional, /kn'dnl/, adj，条件的
11. membership, /'membp/, n，成员关系
12. sequence, /'sikwns/, n，序列
13. identity, /a'dentti/, n，身份
14. object, /'bdkt/, n，对象
15. control flow, /kn'trl/ /fl/, n，控制流

Tags：less全局变量