ifs_example.py

number = int(raw_input('Enter a number between 20 and 0: '))

# Only one of the following statements will print. If a condition
# (like "number < 20") is matched, then only that part of the block
# will run. That's what elif does. Else, if. 
if number < 20:
  print '%d is less than 20' % number
elif number < 10:
  print '%d is less than 10' % number
elif number < 5:
  print '%d is less than 5' % number

print '\n\n--------------------\n\n'



# In this case, all of the applicable conditions will be run,
# beacuse we're setting up a bunch of different comparisons
# that aren't related to eachother.
if number < 20:
  print '%d is less than 20' % number
if number < 10:
  print '%d is less than 10' % number
if number < 5:
  print '%d is less than 5' % number