README.md

Lesson 1

Data Types and Variables

We can print words into our console:

  print("hello world")

Note that quotes mark a string (a list of characters and letters):

  "hello world"

We can also print integers (no quotes):

  print(123)

We can also and floats (no quotes, with a decimal):

  print(123.45)

And we can do math with these numbers:

  print(1 + 2 * 3 / 4 - 5)

Sometimes, we want to store data for later use. We do this with variables:

  a = 5
  b = 6
  c = "Hello World"
  print(a + b)
  print(c)

We can also take inputs from a user, and store them in a variable:

  a = input()
  print(a)

We can convert strings to numbers, and numbers to strings with the int() and str() functions:

  a = int("123")
  b = str(123)
  print(a)
  print(b)

Homework

Write a program that takes in the height and width of a triangle, and prints out the area.

• Must ask user for input (as in the computer prints: “Please enter width:”)
• The area of a triangle is (width * height) / 2
• Use the int() function to convert input to integer

Solution

w = int(input("Please enter the width: "))

h = int(input("Please enter the height: "))

print((w * h) / 2)

What are the results obtained by the following programs:

1

  x = 1
  y = x
  x = 3
  print(x + y)

2

  a = 1
  a = 2
  print(a)

3

  four = 4
  five = 5
  print(four + five)

4

  x = 10
  y = 6
  y = y + 2
  z = x - y
  print(z)

5

  my_variable = '4'
  my_variable = 4
  my_variable = my_variable * 4
  print(my_variable)