Skip to content

Expressions

In python, We can see the value of something by using print like this:

print(3)

The expression passed to the print can be any Python expression. Here are some examples of expression:

1 + 1        # addition
2 - 1        # subtraction
2 * 6        # multiplication

We can compose expressions to make more complicated expressions like, 

52 * 3 + 12 * 9

We can also use parentheses to group expressions: 

(52 * 3) + (12 * 9)

is different from

52 * (3 + 12) * 9

For example, this code prints out the the number of hours in a day: 

print(365 * 24 * 60 * 60)

Quiz 1.1

Write a Python program that prints out the number of minutes in seven weeks.

Answer 
print(7 * 7 * 24 * 60)

Quiz 1.2

Which of the following are valid Python expressions that can be produced starting from Expression? There may be more than one.

  • A) 3
  • B) ((3)
  • C) (1 * (2 * (3 * 4)))
  • D) + 3 3
  • E) (((7)))
Answer
  • A) 3
  • C) (1 * (2 * (3 * 4)))
  • E) (((7)))

Quiz 1.3

Write Python code to print out how far light travels in centimeters after one nanosecond using the multiplication operator.

The speed of light is 299792458 meters per second.
One meter is 100 centimeters.
One nanosecond is one billionth (1/1000000000) of a second.

Answer 
print(299792458 * 100 * (1 / 1000000000))

Answer: 11.1034243704

Back to top