Introduction to Python Week 8

Python Overview

• Created by Guido van Rossum and released in 1991.
• Popular for web development, software development, mathematics, and system scripting.
• Compatible with multiple platforms like Windows, Mac, Linux, and Raspberry Pi.

Why Python?

• Simple, readable syntax similar to English.
• Fewer lines of code needed compared to other languages.
• Utilizes an interpreter system for immediate code execution and rapid prototyping.
• Supports procedural, object-oriented, and functional programming paradigms.

Python Syntax

• Emphasizes readability; commands are completed with new lines rather than semicolons.
• Uses indentation instead of curly brackets to define scopes for loops, functions, and classes.

Comments and Variables

• Comments initiated with #, improving code readability and preventing execution during testing.
• Variables are containers for data values and are created upon first assignment.
• No explicit type declaration is necessary; types can change dynamically.

Type Casting

• Data types can be specified using casting functions.

String Declaration

• Strings can be declared using single or double quotes interchangeably.

Variable Naming Rules

• Can be a single character or descriptive word.
• Must start with a letter or an underscore, cannot start with a number.
• Only contains alphanumeric characters and underscores.
• Case-sensitive; for example, age, Age, and AGE are distinct variables.
• Cannot use reserved Python keywords as variable names.

Multi-word Variable Naming Conventions

• Camel Case: e.g., myVariableName.
• Pascal Case: e.g., MyVariableName.
• Snake Case: e.g., my_variable_name.

Output Variables

• Use the print() function to display variables, which can accept multiple inputs separated by commas.
• The + operator works for number addition and string concatenation.

Data Types

• Integer (int): Whole numbers without decimals, positive or negative, of unlimited length.
• Floating Point (float): Numbers containing decimals, positive or negative.
• String: Enclosed in single or double quotes; displayable through print().

Type Conversion Functions

• int(): Converts to an integer from float or string where applicable.
• float(): Converts to a float from integer, float, or string.
• str(): Converts any data type into a string format.