"Programming in Python"
Chapter 2: Programming in Python
2.1 Introduction to Python
Python is a high-level programming language that is easy to learn and fun to use. It is a popular language used in various fields such as web development, scientific computing, data analysis, artificial intelligence, and more.
2.2 Basic Syntax and Data Types
Basic Syntax: Python's syntax is simple and intuitive. It uses indentation to define block-level structure.
- Variables: In Python, you can assign a value to a variable using the assignment operator (=).
- Print Function: The print() function is used to output text to the screen.
Data Types: Python has several built-in data types:
- Integers: Whole numbers, e.g., 1, 2, 3, etc.
- Floats: Decimal numbers, e.g., 3.14, -0.5, etc.
- Strings: Sequences of characters, e.g., "hello", 'hello', etc. Strings can be enclosed in single quotes or double quotes.
- Boolean: A logical value that can be either True or False.
- List: An ordered collection of items that can be of any data type, including strings, integers, floats, and other lists.
2.3 Operators and Control Structures
Operators: Python has various operators for performing arithmetic, comparison, logical, and assignment operations.
- Arithmetic Operators: +, -, , /, %, *
- Comparison Operators: ==, !=, <, >, <=, >=
- Logical Operators: and, or, not
- Assignment Operators: =, +=, -=, =, /=, %=, *=
Control Structures: Control structures are used to control the flow of a program.
- If-Else Statements: Used for decision-making.
- For Loops: Used for iterating over a sequence.
- While Loops: Used for repeating a block of code.
2.4 Functions and Modules
Functions: A function is a block of code that can be called multiple times from different parts of your program.
- Defining a Function: Use the def keyword to define a function.
- Calling a Function: Call a function by its name followed by parentheses containing any arguments.
Modules: A module is a file that contains a collection of related functions, classes, and variables.
- Importing a Module: Use the import keyword to import a module.
- Using a Module: Access the functions, classes, and variables of a module using the dot notation.
2.5 File Handling
File Handling: Python provides various functions for reading and writing files.
- Opening a File: Use the open() function to open a file.
- Reading from a File: Use the read() method to read from a file.
- Writing to a File: Use the write() method to write to a file.
- Closing a File: Use the close() method to close a file.
2.6 Summary
In this chapter, we learned the basics of programming in Python, including data types, operators, control structures, functions, modules, and file handling.
2.7 Exercises
1. Write a Python program to print "Hello, World!" to the screen.
2. Ask the user for their name and age, and then print out a greeting message.
3. Write a Python program to calculate the area and perimeter of a rectangle.
4. Create a list of numbers and then use a for loop to print out each number.
5. Define a function that takes two numbers as arguments and returns their sum.
2.8 Key Terms
- Variables
- Data Types
- Operators
- Control Structures
- Functions
- Modules
- File Handling
