这些操作符对它们的两侧的值进行比较，并决定它们之间的关系。它们也被称为关系运算符。
假设变量 a = 10，变量b = 20，那么-
| 操作符 | 描述 | 示例 |
|---|---|---|
| == |
如果两个操作数的值相等，则条件变为真
|
(a == b) 不为 true. |
| != |
如果两个操作数的值不相等，则条件变为真
|
|
| <> |
如果两个操作数的值不相等，则条件变为真
|
(a <> b) 为 true. 这类似于 != 运算符 |
| > |
如果左操作数的值大于右操作数的值，则条件为真
|
(a > b) 不为true. |
| < |
如果左操作数的值小于右操作数的值，则条件为真。
|
(a < b) 为 true. |
| >= |
如果左操作数的值大于或等于右操作数的值，则条件为真
|
(a >= b) 不为 true. |
| <= |
如果左操作数的值小于或等于右操作数的值，则条件为真
|
(a <= b) 为 true. |
示例
假设变量 a = 10，变量b = 20，那么 -
#!/usr/bin/python3
a = 21
b = 10
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 less than b" )
else:
print ("Line 3 - a is not less than b")
if ( a > b ):
print ("Line 4 - a is greater than b")
else:
print ("Line 4 - a is not greater than b")
a,b=b,a #values of a and b swapped. a becomes 10, b becomes 21
if ( a <= b ):
print ("Line 5 - a is either less than or equal to b")
else:
print ("Line 5 - a is neither less than nor equal to b")
if ( b >= a ):
print ("Line 6 - b is either greater than or equal to b")
else:
print ("Line 6 - b is neither greater than nor equal to b")
当你执行上面的程序它产生以下结果 -
Line 1 - a is not equal to b Line 2 - a is not equal to b Line 3 - a is not less than b Line 4 - a is greater than b Line 5 - a is either less than or equal to b Line 6 - b is either greater than or equal to b
