Python Coding Challenges

Datetime & Time Calculations easy

Month End Date

Implement a function that returns the last day of the month for a given year and month.

datetime calendar leap-year

Generate CSV row

Implement a function that converts a list of values into a single CSV row with correct quoting and escaping.

csv escaping strings

Parse email header

Write a function that parses a raw email header string and returns sender, recipient, and subject.

parsing strings email

+10 pts 12m

Encode Base64 String

Write a function that encodes a UTF-8 string into a base64 string without using the base64 module.

base64 encoding strings

+8 pts 15m

Parse CSV Row

Implement a robust function that parses a single CSV line into a list of fields, handling double quotes and escaped quotes.

csv parsing strings

Parse Apache log line

Write a function that parses a single Apache access log line into a dictionary with IP, timestamp, request, status, and size.

parsing strings regex

Parse table rows

Implement a function that converts a simple text table into a list of dictionaries.

parsing strings csv

Inner Join Two Tables

Write a function that inner joins two lists of dictionaries on a common key and returns the combined rows.

sql join dictionaries

Create Table Schema

Write a function that creates a SQLite table with a given name and columns, and returns the resulting schema as a list of column definitions.

sqlite schema table

sql window-functions running-total

Cumulative Sum SQL

Write a SQL query to compute cumulative sales totals per product ordered by sale date.

Select All Users

Write a function that connects to an in-memory SQLite database and returns all users as a list of lists.

sqlite sql query

Add column alter

Write a function that connects to an in-memory SQLite database, creates a table, inserts rows, and adds a new column with ALTER TABLE.

sqlite alter-table ddl

SHA256 Hash String

Write a function that returns the SHA256 hexadecimal digest of a given string.

hashing sha256 hashlib

+5 pts 5m

Compute SHA-1 Hash String

Write a function that returns the SHA-1 hash of a string as a 40-character hex string.

sha1 hashlib hashing

constant-time security comparison

Constant Time Compare

Write a function that compares two strings without leaking length or content via timing.

Verify HMAC signature

Implement a function that verifies an HMAC-SHA256 signature for a message and key.

hmac hashlib security

Password Salt Hash

Implement a function that returns a secure salted SHA-256 password hash with a deterministic format.

hashlib sha256 security

SHA1 Hash String

Implement a function that returns the SHA1 hexadecimal digest of an input string.

sha1 hashlib hashing

timing-safe security strings

Constant time compare

Write a function that compares two strings in constant time to avoid timing attacks.

Compute SHA256 Hash String

Implement a function that returns the SHA-256 hex digest of a given input string.

sha256 hashing hashlib

Verify HMAC signature

Implement a function that verifies an HMAC-SHA256 signature for a given message and secret key.

hmac sha256 security