发布于 2015-06-21 10:33:33 | 112 次阅读 | 评论: 0 | 来源: 网络整理
下表列出了所有Python语言支持的逻辑运算符。假设变量a持有10和变量b持有20，则：
| 运算符 | 描述 | 例子 |
|---|---|---|
| and | 所谓逻辑与运算符。如果两个操作数都为真，则条件为真。 | (a and b) 为 true. |
| or | 所谓逻辑OR运算符。如果有两个操作数都为非零，则条件变为真。 | (a or b) 为 true. |
| not | 所谓逻辑非运算符。用反转操作数的逻辑状态。如果条件为true，则逻辑非运算符将为false。 | not(a and b) 为 false. |
试试下面的例子就明白了所有的Python编程语言提供了逻辑运算符：
#!/usr/bin/python
a = 10
b = 20
c = 0
if ( a and b ):
print "Line 1 - a and b are true"
else:
print "Line 1 - Either a is not true or b is not true"
if ( a or b ):
print "Line 2 - Either a is true or b is true or both are true"
else:
print "Line 2 - Neither a is true nor b is true"
a = 0
if ( a and b ):
print "Line 3 - a and b are true"
else:
print "Line 3 - Either a is not true or b is not true"
if ( a or b ):
print "Line 4 - Either a is true or b is true or both are true"
else:
print "Line 4 - Neither a is true nor b is true"
if not( a and b ):
print "Line 5 - Either a is not true or b is not true"
else:
print "Line 5 - a and b are true"
当执行上面的程序它会产生以下结果：
Line 1 - a and b are true
Line 2 - Either a is true or b is true or both are true
Line 3 - Either a is not true or b is not true
Line 4 - Either a is true or b is true or both are true
Line 5 - Either a is not true or b is not true