Variables and Data Types

In programming, a variable is a container that holds a value. Think of it as a labeled box where you store information you'll use later.

Creating Variables

Let's create some variables for financial data:

The = sign doesn't mean "equals" in the mathematical sense - it means "assign the value on the right to the variable on the left."

Variable Naming Rules

Variable names in Python:

• Can contain letters, numbers, and underscores
• Must start with a letter or underscore (not a number)
• Are case-sensitive (stockPrice and stockprice are different)
• Cannot use reserved words like if, for, while

Good vs Bad Variable Names

Data Types in Python

Python automatically determines what type of data you're storing. Understanding these types is crucial for financial work.

Integers (int) - Whole numbers

Floating-Point Numbers (float) - Decimals

Strings (str) - Text

Booleans (bool) - True/False

Practice Exercise

Key Takeaways

• Variables store data that you can use later
• Use descriptive names to make code readable
• Integers are whole numbers (shares, years)
• Floats are decimals (prices, returns)
• Strings are text (ticker symbols, company names)
• Booleans are True/False values (yes/no conditions)

Next, we'll learn how to perform calculations with these variables using arithmetic operations!