??Ask ChatGTP: ?? Python Learning Series 101 Example Code for Each Topic

Yes - we can get the Bite of Python quickly step by step - learn by EXAMPLES below! ??

Introduction - an example of the power of Python:

Here’s a sample Python code that follows a ??functional programming approach to:

? Define a function exp(x, y) - the def command - def exp(x,y)

? Evaluate the function over a range of values using functional programming

? Visualize the results using matplotlib

Example notes: need libs for numpy and matplotlib, use: <<assuming pip is installed>>

pip install matplotlib

pip install numpy

pip stands for "Pip Installs Packages". It’s the package manager for Python, used to install and manage software libraries and dependencies. It's the recommended tool for managing Python packages and comes bundled with Python starting from Python 3.4.

# Python Learning Series - Example Code for Each Topic

Here’s a clear and easy-to-understand list of all Python keywords (reserved words) as of Python 3.12:

Control Flow Keywords

• if — Conditional statement
• else — Alternate branch of an if statement
• elif — Else if (for multiple conditions)
• for — Loop through items
• while — Loop until a condition is False
• break — Exit a loop early
• continue — Skip the rest of the current loop iteration
• pass — Do nothing (placeholder)

Function and Class Keywords

• def — Define a function ??
• return — Return a value from a function
• yield — Return a generator value
• class — Define a class

Exception Handling Keywords

• try — Start a block of code that may raise an error
• except — Handle an error
• finally — Run code whether an error occurs or not
• raise — Manually trigger an error
• assert — Debugging tool for conditions that must be True

Import Keywords

• import — Import a module ??
• from — Import specific parts of a module
• as — Rename an imported module

Variable Scope Keywords

• global — Declare a global variable
• nonlocal — Reference a variable in an outer (non-global) scope

Logical and Comparison Keywords

• and — Logical AND operator
• or — Logical OR operator
• not — Logical NOT operator
• is — Object identity comparison
• in — Membership test (e.g., x in list)

Object Management Keywords

• del — Delete a variable or object
• with — Manage resources (e.g., file handling)

Special Purpose Keywords

• lambda — Create an anonymous function
• True — Boolean True value
• False — Boolean False value
• None — Represents "nothing" or "no value"

Newer Keywords (Python 3.10+)

• match — Start a pattern-matching block (like switch in other languages)
• case — Define patterns within match

?? Important Notes

• Python keywords are case-sensitive. ??
• You cannot use keywords as variable names, function names, or identifiers.

101. Introduction to Python and Installation (at the end)

print("Hello, World! This is Python.") # Basic print statement for intro - silly it goes to you

# 2. Python Syntax and ??Indentation -

<<Note: indentation - 4 spaces - marks a block of code - do not use tabs - def defines a function>>

def greet(name):

if name: # Correct indentation is crucial in Python

print(f"Hello, {name}!")

else:

print("Hello, World!")

greet("Alice")

<<comments: note indentation before if and print, note ':' after else>>

# 3. Variables and Data Types

name = "John" # String variable

days = 365 # Integer variable

pi = 3.14159 # Float variable

print(f"{name} - {days} days in a year - Pi value: {pi}")

# 4. Input and Output Operations

user_input = input("Enter your name: ")

print(f"Welcome, {user_input}!")

# 5. Comments and Documentation

"""

Triple quotes are used for documentation strings (docstrings)

Useful for documenting functions, classes, and modules.

"""

# 6. Type Conversion and Casting

num_str = "42"

num_int = int(num_str) # Converting string to integer

print(num_int * 2)

# 7. Operators and Expressions

x, y = 10, 5

print(f"Addition: {x + y}, Multiplication: {x y}, Power: {x * y}")

# 8. Control Flow: if, else, elif

<<Note: indentation - 4 spaces - marks a block of code>>

score = 85

if score >= 90:

print("Grade: A")

elif score >= 75:

print("Grade: B")

else:

print("Grade: C")

# 9. Loops: for and while

# Using a for loop

<<Note: indentation - 4 spaces - marks a block of code>>

total = 0

for i in range(1, 6):

total += i

print(f"Total sum: {total}")

# Using a while loop

counter = 3

while counter > 0:

print(f"Countdown: {counter}")

counter -= 1

# 10. Break, Continue, and Pass

for i in range(1, 6):

if i == 3:

continue # Skip number 3

print(i)

# 11. Lists: Creating, Accessing, and Modifying

fruits = ["apple", "banana", "cherry"]

fruits.append("orange") # Adding element

print(fruits)

# 12. List Comprehensions

squares = [x**2 for x in range(5)]

print(f"Squares: {squares}")

# 13. Tuples: Immutable Sequences

days = ("Monday", "Tuesday", "Wednesday")

print(f"First day of the week: {days[0]}")

# 14. Sets and Their Operations

set1 = {1, 2, 3}

set2 = {3, 4, 5}

print(f"Union: {set1 | set2}, Intersection: {set1 & set2}")

# 15. Dictionaries: Key-Value Pair Management

person = {"name": "Alice", "age": 30}

person["city"] = "New York"

print(person)

# 16. Advanced Dictionary Methods

print(person.get("age", "Unknown")) # Get method with default value

# 17. Working with Strings

message = " Hello World! "

print(message.strip().upper()) # Remove spaces & convert to uppercase

# 18. String Slicing Techniques

word = "Python"

print(word[0:4]) # Prints 'Pyth'

# 19. Python Collections

from collections import Counter

nums = [1, 2, 2, 3, 3, 3]

print(Counter(nums))

# 20. Functions and Modules

# Defining a function

<<Here starts functional programming - a powerful way to encapsulate code and complex applications - code each function and then call as needed! ??>>

def add_numbers(a, b):

"""Adds two numbers and returns the result."""

return a + b

result = add_numbers(10, 5)

print(f"Sum: {result}")

# Importing modules

import math

print(f"Square root of 16: {math.sqrt(16)}")

# File Handling

# Writing to a file

with open("sample.txt", "w") as file:

file.write("Hello, this is a sample file.")

# Reading from a file

with open("sample.txt", "r") as file:

content = file.read()

print(f"File Content: {content}")

# Appending to a file

with open("sample.txt", "a") as file:

file.write("\nAdding more data.")

# Object-Oriented Programming (OOP)

class Car:

def init(self, brand, model, year):

self.brand = brand

self.model = model

self.year = year

def display_info(self):

print(f"{self.year} {self.brand} {self.model}")

# Creating objects

car1 = Car("Toyota", "Corolla", 2020)

car2 = Car("Honda", "Civic", 2018)

car1.display_info()

car2.display_info()

# Advanced Python Concepts??

# Decorators

def decorator_function(original_function):

def wrapper_function(*args, **kwargs):

print(f"Wrapper executed before {original_function.__name__}")

return original_function(*args, **kwargs)

return wrapper_function

@decorator_function

def display():

print("Display function executed.")

display()

# Generators

def count_up_to(max_value):

count = 1

while count <= max_value:

yield count

count += 1

for number in count_up_to(5):

print(number)

# Context Manager

class FileManager:

def init(self, filename, mode):

self.filename = filename

self.mode = mode

def enter(self):

self.file = open(self.filename, self.mode)

return self.file

def exit(self, exc_type, exc_value, traceback):

self.file.close()

with FileManager("example.txt", "w") as f:

f.write("This is managed by a context manager.")

print("File written successfully.")

??EXTENDING PYTHON ??

# APIs

import requests

response = requests.get("https://jsonplaceholder.typicode.com/posts/1")

print(response.json())

# Data Visualization ??

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]

y = [10, 20, 30, 40, 50]

plt.plot(x, y, marker='o')

plt.title("Sample Data Visualization")

plt.xlabel("X-axis")

plt.ylabel("Y-axis")

plt.show()

# Automation

import pyautogui

pyautogui.alert("Automation with Python is cool!")

PY INSTALL BACKGROUND:

<<Note: unfortunately installing a Py editor is another topic, visual studio code is free/easy>>

GIVE THE STEPS IN A TEXT BLOCK TO INSTALL PYTHON

<<Note: to avoid a messy windows install when >python --version gives an error: >>

??Best to use the option below - MODIFY - to enable adding the py path

????Click on the ADD PY TO ENV VARIABLES BELOW:

**Steps to Install Python**

1. **Download Python Installer**

- Go to the official Python website: [https://www.python.org/downloads/](https://www.python.org/downloads/)

- Click on the latest stable version (recommended for most users).

2. **Run the Installer**

- Open the downloaded .exe file.

- **Check the box that says "Add Python to PATH"** (important for command-line usage).

<<Fix: see above - this option is on the advanced setup - under modify>>

- Click **"Install Now"** for the default installation or **"Customize installation"** for advanced options.

3. **Verify Installation**

- Open **Command Prompt** (Windows) or **Terminal** (macOS/Linux).

- Run the following command to verify Python is installed correctly:

```

python --version

```

Or use python3 --version if python doesn’t work.

4. **Install pip (if not included)**

Python installers typically include pip, but if missing, install it with:

```

python -m ensurepip --upgrade

```

5. **Install Virtual Environment (Recommended for Projects)**

Create a virtual environment to manage dependencies:

```

python -m venv my_project_env

source my_project_env/bin/activate # On Mac/Linux

my_project_env\Scripts\activate # On Windows

```

6. **Test by Installing a Package**

For example, install requests to confirm everything works:

```

pip install requests

```

My env results - typical IT mess of commands!??

7. **Set Environment Variables (If Needed)** <<messy ??>>

If Python isn’t recognized in the command line, manually add its path to your system’s environment variables.

Now you're ready to code with Python! ??