If Statements

If-Elif-Else

Programs can be made to make decisions.

This is called selection.

If-Elif-Else

This is called selection.

In Python this is achieved using:

# Selection using IF-ELIF-ELSE
if age > 30:
  print('You are too old!')
elif age < 20:
  print('You are too young!')
else:
  print('You are the correct age.')

Comparison & Logic Operators

These are used all the time with selection

Operator	Description
==	equal to
!=	not equal to
>	greater than
<	less than
>=	greater or equal to
<=	less or equal to

Operator	Description
and	both conditions must be met
or	either condition must be met

Comparison operators

Logical operators

If Statements

	if num > 10:
	print('This is over 10')
	else:
	print('This is not over 10')

	if num > 10:
	print('This is over 10')
	else:
	print('This is not over 10')

	if num > 10:
	print('This is over 10')
	else:
	print('This is not over 10')

	if num > 10:
	print('This is over 10')
	else:
	print('This is not over 10')

	if num > 10:
	print('This is over 10')
	else:
	print('This is not over 10')

If Statements

If-Elif-Else

If-Elif-Else

If-Elif-Else

Key points (do this or the code will not run!)

Comparison & Logic Operators

These are used all the time with selection

Comparison operators

Logical operators

Example I

Example II

Example III

Example IV

Example V

Tasks I

Tasks II

Tasks III

	if num > 10:
	print('This is over 10')
	elif num == 10:
	print('This is equal to 10')
	else:
	print('This is under 10')

	if num >= 10:
	if num <= 20:
	print('This is between 10 and 20')
	else:
	print('This is over 20')
	else:
	print('This is under 10')

	# Top-Tip: Convert to lowercase
	# =============================

	uppercaseWord = 'PYTHON'
	lowercaseWord = upperCaseWord.lower()
	#or
	lowercaseWord = 'PYTHON'.lower()

	num = int(input("Enter a number between 10 and 20: "))
	if num >= 10 and num <= 20:
	print('Thank you')
	else:
	print('Out of range')

	num = int(input("Enter an even number between 1 and 5: "))
	if num == 2 or num == 4:
	print('Thank you')
	else:
	print('Incorrect')