Storing and Modifying Information (CRUD)

Lesson: Storing and Modifying Information in Python – CRUD Operations

Introduction

In this lesson, we’ll explore how to store, read, update, and delete information in Python. These operations, collectively known as CRUD (Create, Read, Update, Delete), are fundamental tasks in any computer program. We’ll use examples and provide practice assignments to solidify your understanding.

Objectives

By the end of this lesson, you will:

• Understand the concept of variables and data types in Python.
• Learn how to perform CRUD operations with different data types.
• Practice using Python to manipulate variables and data types.

1. Storing Information in Variables

What is a Variable?

A variable is a storage box for information. Variables allow you to store and modify data in your program.

Creating Variables

To create a variable, assign a value to it using the = operator.

Data Types

Python has different types of variables for different kinds of information:

• Integer (int): Whole numbers
• Floating-point (float): Numbers with decimals
• String (str): Text
• Boolean (bool): True or False

Examples:

2. CRUD Operations

Create

Creating a variable involves assigning a value to it.

Read

Reading a variable means accessing its value.

Update

Updating a variable changes its value.

Delete

Deleting a variable removes it from memory.

3. Understanding Numeric Types

Integers

Integers are whole numbers without a decimal point.

Floating-point Numbers

Floating-point numbers have a decimal point.

Example:

4. Strings

Strings are sequences of characters used to store text.

5. Boolean Values

Booleans represent truth values: True or False.

6. Working with Dates and Times

Python provides the datetime module to work with dates and times.

Example: Getting Current Date

Practice Assignments

Assignment 1: Variable Assignment

• Create a variable name and assign your name to it.
• Create a variable age and assign your age to it.
• Print both variables.

Answer Key:

Assignment 2: Data Types

• Create an integer variable num1 with the value 10.
• Create a float variable num2 with the value 20.5.
• Add num1 and num2 and print the result.

Answer Key:

Assignment 3: String Manipulation

• Create a variable first_name with your first name.
• Create a variable last_name with your last name.
• Concatenate both variables to create a full_name and print it.

Answer Key:

Assignment 4: Boolean Values

• Create a boolean variable is_student with the value False.
• Print the variable and its type.

Answer Key:

Assignment 5: Dates and Times

• Import the datetime module.
• Get the current date and print it in a readable format.

Answer Key:

Conclusion

Understanding how to store and manipulate information is crucial in Python programming. Practice these concepts regularly to build a strong foundation in working with variables, data types, and CRUD operations.

Suggestions for further improvement:

a. Try incorporating error handling when performing CRUD operations on variables, like checking if a variable exists before trying to read or delete it.

b. Explore working with other data types in CRUD operations, like lists and dictionaries, for more complex data handling.