Variables

  • An abstraction inside a program that can hold a value.
  • Think of them as containers or boxes for data.
  • They help manage and organize data in your code, making it more organized, readable, and adaptable.

Different Data Types for Variables

  • Integer: Used for numbers used in mathematical operations (e.g., age or temperature).
  • Text (String): Used for text, lists, and words (e.g., name, phone number, or address).
  • Boolean: Used for representing true or false values (e.g., “Is it raining?”).

Correct Way to Name Variables

  • Should be short, descriptive, and easy to distinguish.
  • Must start with a letter or underscore (not a number).
  • Can only have alphanumeric characters or underscores.
  • Are case sensitive.
  • Cannot be Python keywords (e.g., ‘else’).

Hacks

Storing if someone’s pet is a dog:

  • Variable Name: isDog
  • Data Type: Boolean

Storing someone’s birthday:

  • Variable Name: birthday
  • Data Type: Text (String)

Storing the amount of money someone is spending:

  • Variable Name: amountSpent
  • Data Type: Float (for decimal values)

Storing if it is sunny:

  • Variable Name: isSunny
  • Data Type: Boolean

Primitive vs. Collection Data Types

Primitive Data Types

  • int
  • string
  • float
  • boolean

Collection Data Types

  • list
  • dictionary

Concatenation

  • Concatenation is the joining of strings and other types.
  • Example: myFirstName + " " + myLastName

Formatting

  • Allows you to display values using predefined rules.
  • Example: message = "My first name is {0} and my last name is {1}"