25. 15 Best Python Libraries for Beginners with Examples and Tips

Hello friend! 👋 A library (or module) is code that other people already wrote for you. Instead of writing everything from zero, you just import it and use it. This is the real power of Python! 🐍

In this post, you learn 15 libraries that are great for beginners. Each one has a short example you can run right away.

Two Kinds of Libraries

• 📦 Built-in (standard library): Come with Python. No install needed. Just import.
• ⬇️ Third-party: Made by the Python community. Install first with pip.

Install all 8 third-party libraries in this post with one command:

pip install requests numpy pandas matplotlib pillow beautifulsoup4 pygame flask

On Windows, if pip does not work, try:

py -m pip install requests

Quick Overview

#	Library	Install?	Use it for
1	math	Built-in	Math functions
2	random	Built-in	Random numbers, games
3	datetime	Built-in	Date and time
4	json	Built-in	Save and read data
5	pathlib	Built-in	Files and folders
6	turtle	Built-in	Draw shapes
7	tkinter	Built-in	Desktop app with window
8	requests	pip install requests	Get data from the internet
9	numpy	pip install numpy	Fast number calculation
10	pandas	pip install pandas	Tables, Excel, CSV data
11	matplotlib	pip install matplotlib	Charts and graphs
12	Pillow	pip install pillow	Edit images
13	Beautiful Soup	pip install beautifulsoup4	Read data from websites
14	pygame	pip install pygame	Make 2D games
15	Flask	pip install flask	Make websites

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📦 Built-in Libraries

1. math — Math Functions

Square root, pi, round up, round down, and more.

import math

print(math.sqrt(16))    # 4.0
print(math.pi)          # 3.141592653589793
print(math.ceil(4.2))   # 5  (round up)
print(math.floor(4.8))  # 4  (round down)

radius = 3
area = math.pi * radius ** 2
print(round(area, 2))   # 28.27

2. random — Random Numbers

Great for games, quizzes, and picking random items.

import random

print(random.randint(1, 6))      # roll a dice: 1 to 6

fruits = ["apple", "banana", "mango"]
print(random.choice(fruits))     # pick one fruit

random.shuffle(fruits)           # mix the list
print(fruits)

Mini project — guess the number:

import random

secret = random.randint(1, 10)
guess = int(input("Guess a number from 1 to 10: "))

if guess == secret:
    print("Correct! 🎉")
else:
    print(f"Wrong! The number was {secret}.")

3. datetime — Date and Time

Get today's date, add days, and format dates.

from datetime import date, datetime, timedelta

today = date.today()
print(today)                        # e.g. 2026-11-04
print(today + timedelta(days=7))    # one week later

now = datetime.now()
print(now.strftime("%d/%m/%Y %H:%M"))  # e.g. 04/11/2026 09:30

birthday = date(2000, 5, 20)
print((today - birthday).days, "days old")

4. json — Save and Read Data

JSON is a common format to save data and send data between apps.

import json

student = {"name": "Dara", "age": 20, "skills": ["Python", "SQL"]}

# Save to a file
with open("student.json", "w", encoding="utf-8") as f:
    json.dump(student, f, indent=2)

# Read from the file
with open("student.json", encoding="utf-8") as f:
    data = json.load(f)

print(data["name"])     # Dara
print(data["skills"])   # ['Python', 'SQL']

5. pathlib — Files and Folders

Create folders, write files, and find files in an easy way.

from pathlib import Path

folder = Path("my_notes")
folder.mkdir(exist_ok=True)          # create folder if not exist

file = folder / "hello.txt"          # my_notes/hello.txt
file.write_text("Hello Python!", encoding="utf-8")

print(file.read_text(encoding="utf-8"))  # Hello Python!
print(file.exists())                     # True

for py_file in Path(".").glob("*.py"):   # list all .py files
    print(py_file.name)

6. turtle — Draw Shapes

A fun way to learn loops. A small turtle draws on the screen when you move it.

import turtle

t = turtle.Turtle()
t.color("blue")
t.pensize(3)

# Draw a star
for _ in range(5):
    t.forward(150)
    t.right(144)

turtle.done()

7. tkinter — Desktop App with a Window

Build simple apps with buttons and text boxes.

import tkinter as tk

def say_hello():
    label.config(text=f"Hello, {entry.get()}! 👋")

root = tk.Tk()
root.title("My First App")

entry = tk.Entry(root, width=25)
entry.pack(padx=20, pady=10)

tk.Button(root, text="Say Hello", command=say_hello).pack()

label = tk.Label(root, text="")
label.pack(pady=10)

root.mainloop()

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⬇️ Third-Party Libraries (Install with pip)

8. requests — Get Data from the Internet

Download web pages or call an API in one line.

pip install requests

import requests

response = requests.get("https://api.github.com/users/python")
print(response.status_code)   # 200 means OK

data = response.json()
print(data["name"])
print(data["public_repos"], "public repositories")

9. numpy — Fast Number Calculation

Work with many numbers at once. Used in data science and AI.

pip install numpy

import numpy as np

scores = np.array([80, 95, 70, 88])

print(scores.mean())   # 83.25
print(scores.max())    # 95
print(scores + 5)      # [ 85 100  75  93]  add 5 to every score

10. pandas — Work with Tables (Excel, CSV)

Like Excel, but with code. Very popular for data analysis.

pip install pandas

import pandas as pd

df = pd.DataFrame({
    "name": ["Dara", "Sok", "Vuth"],
    "score": [85, 92, 78],
})

print(df)
print(df["score"].mean())     # 85.0
print(df[df["score"] > 80])   # only students with score over 80

df.to_csv("scores.csv", index=False)   # save to CSV file

To read an Excel file, use pd.read_excel("file.xlsx") (also run pip install openpyxl).

11. matplotlib — Charts and Graphs

Turn numbers into a picture.

pip install matplotlib

import matplotlib.pyplot as plt

days = ["Mon", "Tue", "Wed", "Thu", "Fri"]
hours = [1, 2, 1.5, 3, 2]

plt.plot(days, hours, marker="o")
plt.title("My Python Study Hours")
plt.xlabel("Day")
plt.ylabel("Hours")
plt.show()

Change plt.plot to plt.bar to make a bar chart.

12. Pillow — Edit Images

Resize, convert, and save photos. Install name is pillow, but import name is PIL.

pip install pillow

from PIL import Image

img = Image.open("photo.jpg")
print(img.size)                 # (width, height)

small = img.resize((300, 200))
small.save("photo_small.jpg")

gray = img.convert("L")         # black and white
gray.save("photo_gray.jpg")

13. Beautiful Soup — Read Data from Websites

Get titles, links, and text from a web page (web scraping). Use it together with requests. Install name is beautifulsoup4, import name is bs4.

pip install beautifulsoup4

import requests
from bs4 import BeautifulSoup

html = requests.get("https://example.com").text
soup = BeautifulSoup(html, "html.parser")

print(soup.title.text)          # Example Domain

for link in soup.find_all("a"):
    print(link.get("href"))

14. pygame — Make 2D Games

Make your own game with images, sound, and keyboard control.

pip install pygame

import pygame

pygame.init()
screen = pygame.display.set_mode((400, 300))
pygame.display.set_caption("My First Game")
clock = pygame.time.Clock()

x = 200
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT]:
        x -= 5
    if keys[pygame.K_RIGHT]:
        x += 5

    screen.fill((30, 30, 30))
    pygame.draw.circle(screen, (0, 200, 255), (x, 150), 20)
    pygame.display.flip()
    clock.tick(60)               # 60 frames per second

pygame.quit()

Use the left and right arrow keys to move the ball.

15. Flask — Make a Website

Build a small website or web API with only a few lines.

pip install flask

from flask import Flask

app = Flask(__name__)

@app.route("/")
def home():
    return "Hello from Flask! 🐍"

@app.route("/hello/<name>")
def hello(name):
    return f"Hello, {name}!"

if __name__ == "__main__":
    app.run(debug=True)

Run the file, then open http://127.0.0.1:5000 in your browser. Try http://127.0.0.1:5000/hello/Dara too.

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🗺️ Which Library to Learn First?

You want to…	Start with
Practice loops in a fun way	turtle, random
Make a desktop app	tkinter
Make a game	pygame
Work with data, Excel, charts	pandas, numpy, matplotlib
Get data from the internet	requests, Beautiful Soup
Make a website	Flask
Automate files and photos	pathlib, json, Pillow

💡 Tips

• Learn the built-in libraries first. They need no install and are used everywhere.
• Don't name your file the same as a library! A file called random.py or turtle.py will break import random or import turtle.
• Some libraries have a different install name and import name: pip install pillow → import PIL, pip install beautifulsoup4 → import bs4.
• Use a virtual environment for each project, so libraries don't mix: python -m venv venv.
• Save your project's libraries with pip freeze > requirements.txt, and install them again with pip install -r requirements.txt.
• See what you already installed with pip list.
• Use common short names like everyone else: import numpy as np, import pandas as pd, import matplotlib.pyplot as plt.
• Always add encoding="utf-8" when you read or write text files, especially for Khmer text.
• Only scrape websites that allow it, and don't send too many requests too fast.
• Read the official docs and search library name + example — every popular library has many free examples.

Conclusion

Libraries let you do big things with small code: draw, make games, build apps and websites, and work with data. Start with the built-in ones, then install one third-party library that fits what you want to build. Try every example, change it, and make it your own. Happy coding! 🐍

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