tdtdt/pages/python101.md

title : Python 101
author: zvevqx
published: 2025-11-22
cat: code , python 
desc: ressources for python

...


# Python for Beginners

## Introduction

Python is a high-level, interpreted programming language known for its readability and simplicity. It is a great language for beginners due to its straightforward syntax and wide range of applications.

## Getting Started

1. **Install Python**: Download and install Python from the official website. It's available for Windows, macOS, and Linux. [Python Downloads](https://www.python.org/downloads/)

2. **Install a Text Editor or IDE**: A text editor or IDE is where you'll write and run your Python code. Some popular options include IDLE (included with Python), Visual Studio Code, and PyCharm.

## Basic Python Concepts

### Variables

Variables are used to store data. They can hold different types of values, like numbers, strings, and lists.

```python
x = 10  # integer
y = "Hello, World!"  # string
z = [1, 2, 3]  # list
```

### Functions

Functions are reusable blocks of code that perform a specific task. They help break down complex programs into smaller, more manageable parts.

```python
def greet(name):
    print(f"Hello, {name}!")

greet("Alice")  # prints "Hello, Alice!"
```

### Control Flow

Control flow statements, like if/else and for/while loops, determine the order in which code is executed.

```python
for i in range(5):
    print(i)  # prints numbers from 0 to 4

x = 10
if x > 0:
    print("x is positive")  # prints "x is positive"
```

### Data Structures

Python has several built-in data structures, including lists, tuples, and dictionaries.

```python
my_list = [1, 2, 3]  # list
my_tuple = (1, 2, 3)  # tuple
my_dict = {"name": "Alice", "age": 30}  # dictionary
```

### Modules

Modules are files containing Python definitions and statements. They allow you to organize and reuse code.

```python
import math

print(math.sqrt(16))  # prints 4.0
```

## Intermediate Python Concepts

### Object-Oriented Programming

Python supports object-oriented programming (OOP), which is a programming paradigm that uses "objects" to design applications.

```python
class Dog:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def bark(self):
        print("Woof!")

my_dog = Dog("Fido", 5)
my_dog.bark()  # prints "Woof!"
```

### Exception Handling

Exception handling in Python is done using try/except blocks.

```python
try:
    x = 1 / 0
except ZeroDivisionError:
    print("Cannot divide by zero!")
```

### File I/O

Python can read from and write to files using the built-in `open()` function.

```python
with open("myfile.txt", "w") as file:
    file.write("Hello, World!")

with open("myfile.txt", "r") as file:
    print(file.read())  # prints "Hello, World!"
```

## References

- [Python Documentation](https://docs.python.org/3/)
- [Python Variables](https://docs.python.org/3/tutorial/introduction.html#first-steps-towards-programming)
- [Python Functions](https://docs.python.org/3/tutorial/controlflow.html#defining-functions)
- [Python Control Flow](https://docs.python.org/3/tutorial/controlflow.html)
- [Python Data Structures](https://docs.python.org/3/tutorial/datastructures.html)
- [Python Modules](https://docs.python.org/3/tutorial/modules.html)
- [Python Object-Oriented Programming](https://docs.python.org/3/tutorial/classes.html)
- [Python Exception Handling](https://docs.python.org/3/tutorial/errors.html)
- [Python File I/O](https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files)