Python Data Types and Variables

Python Data Types and Variables

Today's Agenda:

​- Do-Now

​- Introduction to Lesson

​- Lesson Objectives

​- Python Data Types

​- What is Syntax?

​- Code Practice

​- Exit Ticket: Project Stem Lesson 1.1 and 1.2

Introduction

You may have heard the word variable in a math class before. In this lesson, we will learn how Python handles different types of data and variables, and how it stores that data.

Lesson Objectives

• Upon successful completion of this lesson, you will be able to:

• Define and utilize variables.

  
  

• Distinguish between the variable types of integer and string.

Python Data Types:

• Integers or int ( any whole number 1, 2 ,77, 200)

• Floats (any decimal point number 1.5, 3.124, 8.999)

• Strings ( "Lets the user type in letters, numbers and words")

• Functions (A function is a block of code which only runs when it is called. You can pass data, known as parameters, into a function.)

• List

​What is Syntax?

​- the set of rules that defines the combinations of symbols that are considered to be correctly structured statements or expressions in that language.

​Example of Python Syntax:

​print(" Welcome to Computer Science! ")

​

​Step 1: Type the keyword print

​

​Step 2: ( ) Add parenthesis

​

​Step 3: (" ") Add quotation marks inside the parenthesis

​

​Step 4: (" Welcome to Computer Science ") Type Welcome to Computer Science in between the parenthesis.

Strings (str)

• Lets the user type in letters, numbers and words

• Not used for calculations

• When doing calculations: be sure to check that your value is a number, not a string

• Always surrounded in quotation marks

Multiple Select

Select all strings:

• greeting = (Hello)

• greeting = ("Please enter your name")

• greeting = (Welcome to Comp Sci)

• greeting = ("Happy Friday!!!")

Multiple Select

Please select all floating point numbers:

• 1.444

• 34567

• 777.980

• 32.0

• 21

What are Variables?

• A name for a spot in the computer’s memory

• This value can change while the program runs

• Different types of data take up different amounts of space in memory

Creating a variable with Python:

• Syntax:

• variable_name = ( value)

• variable_name = (" string_value")

Open Ended

Try it yourself:

first_name = (" Your name ")

age = (" 32 ")

print(" Hey " + first_name + " your age is " + age)

Creating an input statement:

• Anytime we need information from the user we will use an input statement

• Try it:

• first_name = input (" Enter your first name")

• print(first_name)

Open Ended

Adding an input statement:

first_name = input (" Enter your first name ")

age = input(" How old are you? ")

print(" Hey " + first_name + " your age is " + age)

Open Ended

What about numbers?

Try it:

num1 = input("Enter a number: ")

num2 = input("Enter a number: ")

print(num1 + num2)

The Fix: Adding int

• num1 = int(input("Enter a number: "))

• num2 = int(input("Enter a number: "))

• print(num1 + num2)