In Python:
- Any non-zero and non-null values are considered as TRUE, and
- Zero or NULL are considered as FALSE value
Python has 3 types of decision/if-else statements as:
| Statement | Description | Syntax |
|---|---|---|
| if | An if statement consists of a boolean expression followed by one or more statements. Ex:Boolean expression: (x>y) |
if expression: statement(s) |
| if…else | An if statement can be followed by an optional else statement, which executes when the boolean expression (if condition) is FALSE. |
if expression: statement(s) else: statement(s) |
| nested if | if or else if statement can be used inside another if or else if statement(s). |
if expression1:
statement(s)
if expression2:
statement(s)
elif expression3:
statement(s)
else:
statement(s)
else:
statement(s)
|
Ex (nested if-else):
x = 12
if x < 20:
print "Expression value is < 20"
if x == 14:
print "and = 14"
elif x == 12:
print "and = 12"
elif x == 10:
print "and = 10"
elif x < 10:
print "Expression value is < 10"
else:
print "True expression not found"
print "Tata!"
OUTPUT:
Expression value is < 20 and = 12 Tata!