发布于 2015-06-21 10:32:53 | 146 次阅读 | 评论: 0 | 来源: 网络整理
下表列出了所有Python语言支持的比较操作符。假设变量a持有10和变量b持有20，则：
| 运算符 | 描述 | 示例 |
|---|---|---|
| == | 检查两个操作数的值是否相等，如果是，则条件变为真。 | (a == b) 不为 true. |
| != | 检查两个操作数的值是否等相等，如果值不相等，则条件变为真。 | (a != b) 为 true. |
| <> | 检查两个操作数的值是否等相等，如果值不相等，则条件变为真。 | (a <> b) 结果为true。这类似于!=运算符。 |
| > | 检查左操作数的值是否大于右操作数的值，如果是，则条件成立。 | (a > b) 为 true. |
| < | 检查左操作数的值是否小于右操作数的值，如果是，则条件成立。 | (a < b) 为true. |
| >= | 检查左操作数的值是否大于或等于右操作数的值，如果是，则条件成立。 | (a >= b) 不为 true. |
| <= | 检查左操作数的值是否小于或等于右操作数的值，如果是，则条件成立。 | (a <= b) 为 true. |
试试下面的例子就明白了所有的Python编程语言提供的比较操作符：
#!/usr/bin/python
a = 21
b = 10
c = 0
if ( a == b ):
print "Line 1 - a is equal to b"
else:
print "Line 1 - a is not equal to b"
if ( a != b ):
print "Line 2 - a is not equal to b"
else:
print "Line 2 - a is equal to b"
if ( a <> b ):
print "Line 3 - a is not equal to b"
else:
print "Line 3 - a is equal to b"
if ( a < b ):
print "Line 4 - a is less than b"
else:
print "Line 4 - a is not less than b"
if ( a > b ):
print "Line 5 - a is greater than b"
else:
print "Line 5 - a is not greater than b"
a = 5;
b = 20;
if ( a <= b ):
print "Line 6 - a is either less than or equal to b"
else:
print "Line 6 - a is neither less than nor equal to b"
if ( b >= a ):
print "Line 7 - b is either greater than or equal to b"
else:
print "Line 7 - b is neither greater than nor equal to b"
当执行上面的程序它会产生以下结果：
Line 1 - a is not equal to b
Line 2 - a is not equal to b
Line 3 - a is not equal to b
Line 4 - a is not less than b
Line 5 - a is greater than b
Line 6 - a is either less than or equal to b
Line 7 - b is either greater than or equal to b