How to use if statement in Python
If statement
The if statement lets us do the conditional statement. If a condition is true the corresponding code block will execute while if the condition is evaluated to false the same code block would not get executed.
name = 'java2s.com'
if name.endswith('2s.com'):
print 'Hello, java2s.com'
The code above generates the following result.
else Clauses
We can add an alternative, with the else clause.
name = 'java2s.com'
if name.endswith('2s.com'):
print 'Hello, java2s.com'
else: # w w w . ja v a2 s .c o m
print 'Hello, stranger'
The code above generates the following result.
elif Clauses
To check for several conditions, you can use elif, which is short for "else if." It is a combination of an if clause and an else clause?an else clause with a condition.
We can use elif to build ladder if statement.
num = 2# from w w w .j a v a2 s. c om
if num > 0:
print 'The number is positive'
elif num < 0:
print 'The number is negative'
else:
print 'The number is zero'
The code above generates the following result.
Nesting Blocks
We can have if statements inside other if statement blocks, as follows:
number = 10# w ww . ja v a 2 s . c om
if number <= 10:
if number >= 1:
print 'Great!'
else:
print 'Wrong!'
else:
print 'Wrong!'
name = 'java2s.com'
if name.endswith('2s.com'):
if name.startswith('java'):
print 'Hello, java2s.com'
elif name.startswith('pthon.'):
print 'Hello, python'
else:
print 'Hello, 2s.com'
else:
print 'Hello, stranger'
The code above generates the following result.
