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Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to Calculate the Average of a List of Numbers in Python
Compute the arithmetic mean of a numeric list using Python's built-in sum() and len() functions, returning 0.0 for an empty list.
def calculate_average(numbers):
if not numbers:
return 0.0
return sum(numbers) / len(numbers)
if __name__ == "__main__":
sample_numbers = [10, 20, 30, 40, 50]
result = calculate_average(sample_numbers)
print(f"Average: {result}")How to Rotate a List in Python
Rotate a list to the right by k positions using Python's list slicing and modulo arithmetic.
def rotate_list_right(lst, k):
if not lst:
return lst
k = k % len(lst)
return lst[-k:] + lst[:-k] if k != 0 else lst
if __name__ == "__main__":
sample = [1, 2, 3, 4, 5, 6, 7]
for k in [0, 1, 3, 8, 20]:
print(f"k={k}: {rotate_list_right(sample, k)}")Rotate List Left by k Positions in Python
Rotates a list left by k positions using slicing and modulo arithmetic to handle large k safely.
def rotate_left(lst, k):
if not lst:
return []
k = k % len(lst)
return lst[k:] + lst[:k]
if __name__ == "__main__":
my_list = [1, 2, 3, 4, 5]
k = 2
result = rotate_left(my_list, k)
print(f"Original: {my_list}")
print(f"After rotating left by {k}: {result}")Try Except ValueError in Python: Handle Conversion Errors
Catch ValueError exceptions when converting strings to integers or performing arithmetic, returning None on failure instead of crashing.
def convert_to_int(value):
try:
return int(value)
except ValueError as error:
print(f"Conversion failed: {error}")
print(f"Problem value was: {repr(value)}")
return None
def divide_numbers(numerator, denominator):
try:
result = numerator / denominator
retur…How to Use IntEnum Arithmetic for Priority Levels in Python
Demonstrates Python IntEnum arithmetic for priority levels, showing how enum members behave like integers in calculations and comparisons.
from enum import IntEnum
class Priority(IntEnum):
LOW = 1
MEDIUM = 5
HIGH = 10
CRITICAL = 20
if __name__ == "__main__":
current = Priority.MEDIUM
boosted = current + 3
lowered = current - 2
doubled = current * 2
print(f"Current: {current} ({current.value})")
print(f"Boosted (…Find Missing Number in Python Sequence 1 to N
Find the missing number from a list containing numbers 1 to N using the arithmetic sum formula.
def find_missing_number(nums, n):
expected_sum = n * (n + 1) // 2
actual_sum = sum(nums)
return expected_sum - actual_sum
if __name__ == "__main__":
n = 10
numbers = [1, 2, 3, 4, 5, 6, 7, 9, 10]
missing = find_missing_number(numbers, n)
print(f"The missing number is: {missing}")How to Generate an Arithmetic Progression List in Python
Generates a list of terms in an arithmetic progression using a list comprehension.
def generate_ap(start, difference, count):
"""Generate a list of n terms in an arithmetic progression."""
return [start + i * difference for i in range(count)]
if __name__ == "__main__":
ap = generate_ap(3, 5, 6)
print(ap)How to Rotate an Array by k Steps in Python
This code rotates a list to the right by k positions using modulo arithmetic to handle k larger than the list length.
def rotate_array(nums, k):
if not nums:
return []
n = len(nums)
k = k % n
return nums[-k:] + nums[:-k] if k else nums[:]
if __name__ == "__main__":
arr = [1, 2, 3, 4, 5, 6]
k = 2
result = rotate_array(arr, k)
print(f"Original: {arr}")
print(f"Rotated by {k}: {result}")How to Create an Infinite Arithmetic Sequence Generator in Python
Build a memory-efficient generator that yields an infinite arithmetic progression and extract the first N values with list comprehension.
"""Count generator infinite arithmetic progression"""
def arithmetic_counter(start=0, step=1):
"""Generate an infinite arithmetic sequence."""
current = start
while True:
yield current
current += step
if __name__ == "__main__":
counter = arithmetic_counter(1, 3)
result = [next(c…How to Find Stale GitHub Issues in Python
Filter a list of GitHub issues to find those not updated within a configurable number of days using Python datetime arithmetic.
import os
from datetime import datetime, timezone, timedelta
import re
# Simulated GitHub issue data structure
SAMPLE_ISSUES = [
{"number": 101, "title": "Login button not working", "updated_at": "2025-06-01T12:00:00Z", "assignee": "alice"},
{"number": 102, "title": "Fix database migration error", "updated_at…How to Hash a User ID to an Experiment Bucket in Python
Deterministically map a user ID to one of N experiment buckets using MD5 hashing and modulo arithmetic.
import hashlib
def hash_to_bucket(user_id: str, num_buckets: int = 10) -> int:
"""Deterministically map a user_id to a bucket (0 to num_buckets-1)."""
digest = hashlib.md5(user_id.encode("utf-8")).hexdigest()
return int(digest[:8], 16) % num_buckets
if __name__ == "__main__":
# Mock experiment: split…Browse by section
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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
- Pick a topic section — strings, lists, files, functions, and more
- Open a sample, read How it works, and copy the code block
- 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.