Python OR Operator takes at least two boolean expressions and returns True if any one of the expressions is True. If all the expressions are False then it returns False.
Flowchart of Python OR Operator
Truth Table for Python OR Operator
| Expression 1 | Expression 2 | Result |
|---|---|---|
| True | True | True |
| True | False | True |
| False | True | True |
| False | False | False |
Using Python OR Operator with Boolean Expression
Python OR operator returns True in any one of the boolean expressions passed is True.
Example: Or Operator with Boolean Expression
Python3
bool1 = 2>3bool2 = 2<3 print('bool1:', bool1)print('bool2:', bool2) # or operatorOR = bool1 or bool2print("OR operator:", OR) |
bool1: False bool2: True OR operator: True
Using Python OR Operator in if
We can use the OR operator in the if statement. We can use it in the case where we want to execute the if block if any one of the conditions becomes if True.
Example: Or Operator with if statement
Python3
# or operator with ifdef fun(a): if a >= 5 or a <= 15: print('a lies between 5 and 15') else: print('a is either less than 5 or greater than 15') # driver codefun(10)fun(20)fun(5) |
a lies between 5 and 15 a lies between 5 and 15 a lies between 5 and 15
In the above output, we can see that the code for the if statement is executed always. This is because for every value of a, one of the boolean expressions will always be True and the else block will never get executed.
Python OR Operator – Short Circuit
The Python Or operator always evaluates the expression until it finds a True and as soon it Found a True then the rest of the expression is not checked. Consider the below example for better understanding.
Example: Short Circuit in Python OR Operator
Python3
# short circuit in Python or operatordef true(): print("Inside True") return True def false(): print("Inside False") return False case1 = true() or false()print("Case 1")print(case1)print() case2 = true() or true()print("Case 2")print(case2)print() case3 = false() or false()print("Case 3")print(case3)print() case4 = false() or true()print("Case 4")print(case4) |
Inside True Case 1 True Inside True Case 2 True Inside False Inside False Case 3 False Inside False Inside True Case 4 True
From the above example, we can see that the short circuit or lazy evaluation is followed. In case1 and case2, the second expression is not evaluated because the first expression returns True, whereas, in case3 and case4 the second expression is evaluated as the first expression does not returns True.
