What are the logical operators in Python?

What are the logical operators in Python?

Logical operators in Python are used to perform logical comparisons on expressions and return Boolean values ​​(True or False). There are three commonly used logical operators in Python: and, or and not.

1. and operator
   The and operator is used to check whether all operands are true (True). The and operator returns True only if all operands are true; otherwise it returns False. The following is a sample code:

a = 10
b = 20
c = 30

if a > 0 and b > 0 and c > 0:
    print("所有变量都大于0")
else:
    print("至少有一个变量不大于0")

The output result is: all variables are greater than 0. Because a, b, and c are all greater than 0, the and operator returns True.

2. or operator
   or operator is used to check whether all operands are true (True). The or operator returns True only if at least one operand is true; otherwise it returns False. The following is a sample code:

a = 10
b = 20
c = 30

if a > 100 or b > 100 or c > 100:
    print("至少有一个变量大于100")
else:
    print("所有变量都不大于100")

The output result is: all variables are not greater than 100. Because a, b, and c are not greater than 100, the or operator returns False.

3. not operator
   The not operator is used to negate a single operand. If the operand is true (True), the not operator returns False; if the operand is false (False), the not operator returns True. The following is a sample code:

flag = False

if not flag:
    print("flag为False")
else:
    print("flag为True")

The output result is: flag is False. Because the negation result of flag is True, the not operator returns True.

Logical operators are often used in Python's conditional statements. They can help us process logical comparisons more conveniently and simplify code logic. In actual development, we often need to use logical operators to determine whether multiple conditions are met at the same time or whether at least one condition is met.

Please note that logical operators have short-circuiting properties. For the and operator, if the first operand is false, the subsequent operands will not be executed; for the or operator, if the first operand is true, the subsequent operands will not be executed. This short-circuit characteristic can help us improve code execution efficiency, especially when dealing with complex logical judgments.

Summary:
Logical operators in Python include and, or and not. The and operator requires all operands to be true and returns True; the or operator returns True as long as one operand is true; the not operator negates the operands. Logical operators can help us perform logical comparisons and conditional judgments more conveniently, improving the readability and efficiency of the code.

I hope this article will help you understand the logical operators in Python!

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