Conditionals

Python implements conditionals via if, elif (short for “else if”) and else. Use an if statement to control whether some block of code is executed or not. Let’s consider the boundary between the Antiquity and the Middle Ages:

year = 830
if year > 476:
    print('year', year, 'falls into the medieval era')

Let’s modify the year:

year = 205
if year > 476:
    print('year', year, 'falls into the medieval era')

Add an else statement:

year = 205
if year > 476:
    print('year', year, 'falls into the medieval era')
else:
    print('year', year, 'falls into the classical antiquity period')

Add an elif statement:

year = 1500
if year > 1450:
    print('year', year, 'falls into the modern era')
elif year > 476:
    print('year', year, 'falls into the medieval era')
else:
    print('year', year, 'falls into the classical antiquity period')

What is the problem with the following code?

grade = 85
if grade >= 70:
    print('grade is C')
elif grade >= 80:
    print('grade is B')
elif grade >= 90:
    print('grade is A')