Reference library

Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

13 matches
Lists & loops easy

Find Minimum Value in a List in Python

This code defines a function that finds and returns the minimum value in a list of numbers, handling empty lists gracefully by returning None.

minimum lists iteration
Python
def find_minimum(numbers):
    """
    Find and return the minimum value in a list of numbers.
    
    Args:
        numbers: List of numeric values
        
    Returns:
        The minimum value, or None if the list is empty
    """
    if not numbers:
        return None
    min_value = numbers[0]
    for num in n…
13 0 Open
Lists & loops easy

Generate Data Helper for Beginners in Python

Define two functions that create a random list of integers and then compute basic summary statistics like count, total, average, maximum, and minimum using simple loops.

random loops lists
Python
from random import randint

def build_dataset(size: int, max_val: int) -> list[int]:
    data = []
    for _ in range(size):
        data.append(randint(1, max_val))
    return data

def summarize(data: list[int]) -> dict[str, float]:
    total = 0
    maximum = data[0]
    minimum = data[0]
    for value in data:
   …
13 0 Open
Lists & loops easy

How to Normalize a List of Numbers to the 0-1 Range in Python

Scale a list of numbers so the minimum becomes 0 and the maximum becomes 1 using min-max normalization.

normalization lists data-science
Python
def min_max_normalize(values):
    """Normalize a list of numbers to the [0, 1] range."""
    if not values:
        return []
    min_val = min(values)
    max_val = max(values)
    if min_val == max_val:
        return [0.0] * len(values)
    return [(x - min_val) / (max_val - min_val) for x in values]


if __name__…
12 0 Open
Lists & loops easy

How to Validate List Data in Python

A beginner-friendly validation helper that checks if data is a list, enforces minimum length, and optionally verifies item types with clear error messages.

validation lists loops
Python
def validate_data(data, expected_types=None, min_length=1):
    """Validate that data is a non-empty list and optionally check item types."""
    if not isinstance(data, list):
        return False, f"Expected a list, got {type(data).__name__}"
    
    if len(data) < min_length:
        return False, f"List must have…
16 0 Open
Files & data easy

How to Filter Files by Extension and Size in Python

Use pathlib to list files in a directory, filter by extension or minimum size, and return matching names or (name, size) pairs.

pathlib filesystem filtering
Python
from pathlib import Path

def filter_files_by_extension(directory: str, extension: str) -> list:
    """Return a list of file names in directory with the given extension."""
    path = Path(directory)
    return [f.name for f in path.iterdir() if f.is_file() and f.suffix == extension]

def filter_files_by_size(directo…
13 0 Open
Algorithms & data structures medium

Binary Search for Ship Capacity in Python

Use binary search to find the minimum ship capacity that can transport all packages within a given number of days.

binary search greedy capacity
Python
def ship_within_days(weights, days):
    def can_ship(capacity):
        current = 0
        needed_days = 1
        for weight in weights:
            if current + weight > capacity:
                needed_days += 1
                current = 0
            current += weight
        return needed_days <= days

    low …
13 0 Open
Algorithms & data structures medium

Binary Search on Answer in Python: Koko Eating Bananas

Find the minimum eating speed so Koko finishes all banana piles within a given hour limit using binary search on the answer.

binary-search algorithms search
Python
import math

def min_eating_speed(piles, h):
    """Return minimum integer eating speed K so Koko finishes within h hours."""
    def hours_needed(speed):
        return sum(math.ceil(p / speed) for p in piles)

    low, high = 1, max(piles)
    while low < high:
        mid = (low + high) // 2
        if hours_needed…
15 0 Open
Algorithms & data structures medium

Find Minimum in Rotated Sorted List in Python

Uses binary search to find the minimum element in a rotated sorted list in O(log n) time.

binary-search minimum rotated-array
Python
def find_min(nums):
    left, right = 0, len(nums) - 1
    while left < right:
        mid = (left + right) // 2
        if nums[mid] > nums[right]:
            left = mid + 1
        else:
            right = mid
    return nums[left]


if __name__ == "__main__":
    rotated = [4, 5, 6, 7, 0, 1, 2]
    print(f"Minimu…
13 0 Open
Algorithms & data structures medium

How to Find Minimum Swaps to Sort an Array in Python

Calculate the minimum number of adjacent-free swaps needed to sort a permutation array using cycle detection in Python.

sorting cycles greedy
Python
def min_swaps_to_sort(arr):
    n = len(arr)
    arr_pos = sorted((val, idx) for idx, val in enumerate(arr))
    visited = [False] * n
    swaps = 0

    for i in range(n):
        if visited[i] or arr_pos[i][1] == i:
            continue

        cycle_size = 0
        j = i
        while not visited[j]:
            …
13 0 Open
Algorithms & data structures easy

Rearrange array alternately max min in Python

Rearranges a sorted list so its elements alternate between the current maximum and current minimum using two pointers in O(n) time.

two-pointers array sorting
Python
def rearrange_alternately(arr):
    """
    Rearrange sorted array so elements alternate: max, min, next max, next min...
    Returns a new list in O(n) time using O(n) space.
    """
    n = len(arr)
    result = []
    left, right = 0, n - 1
    while left <= right:
        if left == right:
            result.appen…
14 0 Open
ML engineering pipelines medium

Bayesian Optimization in Python: A Simplified Mock Implementation

A toy Bayesian optimization loop with a Gaussian process prior, expected improvement acquisition, and noisy sampling to find a function's minimum.

bayesian-optimization gaussian-process hyperparameter-tuning
Python
import random
import math

class BayesianOptimizer:
    def __init__(self, noise=0.1):
        self.noise = noise
        self.observations = []
    
    def objective(self, x):
        return (math.sin(3*x) + 0.5*x) / (1 + x**2)
    
    def gaussian_process_prior(self, x1, x2, length_scale=0.5):
        return math.…
12 0 Open
A/B testing & experimentation easy

How to Calculate Minimum Sample Size for a T-Test in Python

Compute the minimum sample size per group for a two-sample t-test using effect size, significance level, and statistical power.

sample-size statistics ab-testing
Python
import math
from scipy.stats import norm


def min_sample_size(effect_size, alpha=0.05, power=0.8):
    """
    Calculate minimum sample size for a two-sample t-test (equal groups).

    Args:
        effect_size: Cohen's d (standardized mean difference)
        alpha: significance level (Type I error)
        power: …
15 0 Open
Auth & security at scale easy

Enforce TLS 1.2 Minimum in Python

Create an SSL context with a minimum TLS version of 1.2 to enforce secure connections.

tls ssl security
Python
import ssl

def get_min_tls_version():
    context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
    context.minimum_version = ssl.TLSVersion.TLSv1_2
    return context.minimum_version

if __name__ == "__main__":
    min_version = get_min_tls_version()
    print(f"Minimum TLS version set to: {min_version.name} (value: {mi…
13 0 Open

Browse by section

Each section groups closely related Python snippets.

Guide: free Python code samples library

Copy-ready Python snippets for learners and developers

PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.

How to use this library

  1. Pick a topic section — strings, lists, files, functions, and more
  2. Open a sample, read How it works, and copy the code block
  3. Run it in the IDE, tweak values, then take a related quiz or tutorial lesson

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.