1, If statements

if condition:

   xxxx

Example:

name='alibaba'

if name=='alibaba':

   print('My name is alibaba')

2, else statements

Example:

name='alibaba'

if name=='alibaba':

   print('My name is alibaba')

else:

   print('Who are you?')

3, elif statements (= else if)

age=20

if age<15:

   print('You are young')

elif age<30:

   print('You are junior')

elif age<50:

   print('Your are senior')

else:

   print('You are old')

Keep in mind: not forget the ":" after the definition of a condition