L2 Data Types

Think about different containers in your kitchen: some hold water, others hold flour, and some store spices. In Python, data types are like these containers—they define what kind of information can be stored.

Python has several data types, including integers (whole numbers), floats (decimal numbers), strings (text), and more. Understanding data types helps you store and use values correctly.💡 Analogy: Data types are like different compartments in a school bag—books go in one pocket, pens in another, and lunch in another. Each type of data has its own "pocket" in Python.

Learning Objectives

1. Identify different data types in Python.

2. Use the type() function to check the type of a variable.

3. Understand why different data types exist and how they are used in programming.

Key Terms

• Data types – Categories of data that define what kind of value a variable can store (e.g., numbers, text).

• Integers (int) – Whole numbers (e.g., 5, 10, -3), used for counting and calculations.

• Floats (float) – Numbers with decimals (e.g., 3.14, -2.5), used for precise calculations.

• Strings (str) – Text-based data, such as "hello" or "Python", stored using quotation marks.

• type() function – A built-in function used to check the type of a variable, helping programmers understand the data they are working with.

Example

print(type(5))        # Output: <class 'int'>

print(type(3.14))     # Output: <class 'float'>

print(type("hello"))  # Output: <class 'str'>

🛑 Common Mistakes

1. Forgetting to convert types: age = input("Enter your age: ") stores input as a string, so age + 5 ❌ will cause an error. Use int(age) + 5 ✅.

2. Mixing strings and numbers improperly: "I am " + 25 ❌ causes an error; use "I am " + str(25) ✅.