Python Practice Problems
Core Python for data manipulation and automation.
581Total problems
208Easy
251Medium
122Hard
Python is one of the most frequently tested skills in data analyst, data engineer and data science interviews — Core Python for data manipulation and automation. Whether you're preparing for a timed technical screen or a take-home assignment, being able to write correct, efficient python under pressure is often what separates candidates who move forward from those who get filtered out early. That's exactly what this page is built for: a permanent, focused practice ground for python, not just another filter on a mixed list.
DataVix's Python problem set is organised into three difficulty tiers — Easy, Medium and Hard — so you can follow a structured practice roadmap instead of solving questions at random. Start with the 208 Easy problems to get comfortable with core syntax and concepts, move on to the 251 Medium problems once you're confident, and finish with the 122 Hard problems that mirror the trickiest real interview rounds. Every problem runs entirely in your browser with instant feedback, hints you can reveal one at a time, and — for enrolled students — a fully worked official solution, so you always know not just whether your answer was right, but why.
Solving Python problems repeatedly, rather than only reading about python, is what actually moves the needle on interview performance: interviewers are evaluating how you think under pressure, not just whether you can recite syntax. Our questions are modeled on real interview patterns reported at companies including Amazon, Google, Meta, Microsoft, Flipkart, TCS, so the practice you put in here transfers directly to the kind of prompts you'll actually be asked. Each problem also lists the topics and companies it's tagged with, so you can drill a specific weak spot — joins, window functions, string manipulation, whatever it may be — instead of solving everything in order.
Use the search, difficulty, topic and sort controls below to build your own python practice session, or work straight down the list from Easy to Hard. New problems are added regularly, and this page updates automatically the moment they go live — no need to keep checking a separate list.
Identify the Type
Variables & Data Typestype()
Python
Easy
75%
4.4K
Safe String to Integer
Variables & Data Typestype casting
Python
Easy
89%
4.7K
List vs Tuple Mutability
Variables & Data Typesmutability
Python
Easy
80%
7.4K
Same Object or Just Equal?
Variables & Data Typesidentity vs equality
Python
Medium
46%
7.6K
Unpack and Swap
Variables & Data Typesmultiple assignment
Python
Easy
82%
5.9K
Truthy or Falsy?
Variables & Data Typesboolean coercion
Python
Easy
82%
7.1K
Chained Comparison Check
Variables & Data Typeschained comparisons
Python
Medium
62%
7.2K
Augmented Balance Update
Variables & Data Typesaugmented assignment
Python
Easy
89%
4.8K
Constant Naming Audit
Variables & Data Typesnaming conventions
Python
Easy
75%
9.1K
None or Default
Variables & Data TypesNone handling
Python
Easy
74%
8.2K
Format Currency with F-Strings
Variables & Data Typesf-strings
Python
Easy
77%
9.2K
Binary, Hex and Octal Literal Reader
Variables & Data Typesnumber bases
Python
Medium
60%
3K
Complex Number Magnitude
Variables & Data Typescomplex numbers
Python
Medium
46%
4.6K
The Float Precision Trap
Variables & Data Typesfloating point
Python
Medium
62%
5.1K
Deep Copy vs Shallow Copy
Variables & Data Typescopying
Python
Hard
31%
3.2K
Variable Scope Leak
Variables & Data Typesscope
Python
Hard
37%
4.1K
Type Coercion in Concatenation
Variables & Data Typestype casting
Python
Medium
49%
4.5K
Set vs List: Deduping Without Losing Order
Variables & Data Typessets vs lists
Python
Medium
55%
4.9K
Unpacking a Multi-Value Return
Variables & Data Typestuple unpacking
Python
Easy
73%
4.1K
Validate and Convert Age Input
Input & Outputinput validation
Python
Medium
50%
2.7K
Dict Key Existence vs Falsy Value
Variables & Data Typesdictionaries
Python
Hard
25%
6.4K
Greet the User
Input & Outputprint()
Python
Easy
85%
9.9K
Custom Separators and End Characters
Input & Outputprint() arguments
Python
Easy
89%
5.7K
Parse a CSV Input Line
Input & Outputparsing user input
Python
Medium
45%
6.8K
Read Multiple Numbers from One Line
Input & Outputparsing user input
Python
Easy
82%
5.5K
Format a Fixed-Width Table Row
Input & Outputstring formatting
Python
Medium
50%
3.9K
Echo Lines with Numbers
Input & Outputstring formatting
Python
Easy
76%
6.7K
Safe Division with a User-Friendly Message
Input & Outputerror output
Python
Medium
49%
7.8K
Build a Text Progress Bar
Input & Outputstring building
Python
Medium
53%
2.9K
Mask Sensitive Output
Input & Outputstring slicing
Python
Easy
77%
8.6K
Summarize Multi-Line Input
Input & Outputaggregating text
Python
Medium
47%
5.8K
Fill a Message Template
Input & Outputstring formatting
Python
Easy
82%
8.2K
Validate a Menu Choice from Input
Input & Outputinput validation
Python
Medium
57%
7.7K
Redact and Format a Log Line
Input & Outputstring processing
Python
Hard
26%
2.1K
Wrap Text to a Fixed Width
Input & Outputtext wrapping
Python
Hard
25%
6.2K
Floor Division vs True Division
Operatorsarithmetic operators
Python
Easy
79%
7.9K
Modulo for Cyclic Indexing
Operatorsmodulo
Python
Easy
83%
8K
Power Operator and Perfect Squares
Operatorsexponentiation
Python
Easy
78%
4.1K
Loan Eligibility with Logical Operators
Operatorslogical operators
Python
Medium
60%
8.2K
Short-Circuit Evaluation for Safe Lookup
Operatorsshort-circuit evaluation
Python
Medium
58%
5.2K
Bitwise Flags for Permissions
Operatorsbitwise operators
Python
Hard
26%
1.6K
Bit Shifts for Fast Powers of Two
Operatorsbitwise shift
Python
Medium
58%
3.1K
Membership Operator Blocklist Check
Operatorsmembership operators
Python
Easy
77%
9.1K
Identity Operator for Cache Hits
Operatorsidentity operators
Python
Medium
64%
4.7K
Ternary Operator for Pass/Fail Grading
Operatorsconditional expressions
Python
Easy
86%
9.1K
Operator Precedence Puzzle
Operatorsoperator precedence
Python
Medium
49%
3.2K
Walrus Operator While Filtering
Operatorsassignment expressions
Python
Hard
28%
5.8K
Comparison Operators for Grade Bands
Operatorscomparison operators
Python
Medium
49%
6.8K
XOR to Toggle Boolean Flags
Operatorsbitwise XOR
Python
Hard
24%
4.2K
Combined Operators: Discount Calculator
Operatorsmixed operatorsBusiness Logic
Python
Medium
51%
4.3K
Even or Odd Classifier
Conditional Statementsif/else
Python
Easy
82%
7.5K
Positive, Negative, or Zero
Conditional Statementsif/elif/else
Python
Easy
83%
5.7K
Leap Year Checker
Conditional Statementsnested conditionals
Python
Easy
82%
8.3K
Largest of Three Numbers
Conditional Statementsnested conditionals
Python
Easy
79%
4.1K
Exam Grade Bucketer
Conditional Statementsif/elif/else
Python
Easy
75%
5.8K
Voting Eligibility Check
Conditional Statementsif/else
Python
Easy
72%
9.8K
Triangle Validity Checker
Conditional Statementsif/else
Python
Easy
73%
4K
Ternary Rewrite: Absolute Value
Conditional Statementsternary operator
Python
Easy
85%
4.4K
Vowel or Consonant
Conditional Statementsmembership check
Python
Easy
75%
5K
Season From Month Number
Conditional Statementschained comparisons
Python
Easy
73%
9K
Password Strength Checker
Conditional Statementsguard clauses
Python
Medium
60%
7.9K
BMI Category Classifier
Conditional Statementsif/elif/else
Python
Medium
54%
6.8K
Shipping Fee Tiers
Conditional StatementsBusiness Logic
Python
Medium
56%
7.7K
In-Range Check With Chained Comparisons
Conditional Statementschained comparisons
Python
Medium
51%
8.1K
Nested If Decision Tree: Loan Eligibility
Conditional Statementsnested conditionalsBusiness Logic
Python
Medium
51%
7K
Day of Week From Number With Weekend Flag
Conditional Statementsif/elif/else
Python
Medium
51%
7K
Loyalty Discount Tier Calculator
Conditional StatementsBusiness Logic
Python
Medium
45%
7K
Rock Paper Scissors Winner
Conditional Statementsnested conditionals
Python
Medium
49%
7.4K
Guard Clauses: Validate User Registration
Conditional Statementsguard clauses
Python
Medium
59%
4.3K
Truthy/Falsy Branching: Config Defaults
Conditional Statementstruthy/falsy
Python
Medium
61%
3.5K
Triangle Type Classifier
Conditional Statementsnested conditionals
Python
Hard
39%
4.4K
Progressive Tax Bracket Calculator
Conditional StatementsBusiness Logicnested conditionals
Python
Hard
35%
4.9K
Multi-Criteria Employee Bonus Eligibility
Conditional StatementsBusiness Logicnested conditionals
Python
Hard
24%
6.9K
Traffic Light State Machine (match-case)
Conditional Statementsmatch-case
Python
Hard
36%
4.2K
Simple Command Parser (match-case)
Conditional Statementsmatch-case
Python
Hard
28%
6K
Sum of First N Natural Numbers
Loopsfor loopaccumulator
Python
Easy
88%
6.3K
Factorial Using a Loop
Loopsfor loopaccumulator
Python
Easy
77%
8.9K
Print a Multiplication Table
Loopsfor looppattern printing
Python
Easy
79%
8.5K
Count Vowels in a String
Loopsfor loop
Python
Easy
83%
7.4K
Reverse a String Using a Loop
Loopsfor loop
Python
Easy
78%
5.7K
Find Maximum in a List Using a Loop
Loopsfor loop
Python
Easy
88%
4.8K
Print Even Numbers in a Range
Loopsrange()
Python
Easy
79%
5.1K
Sum of Digits of a Number
Loopswhile loop
Python
Easy
83%
4.9K
Print a Simple Number Triangle Pattern
Loopsnested loopspattern printing
Python
Easy
73%
6.8K
Countdown Timer Using a While Loop
Loopswhile loop
Python
Easy
76%
9.6K
Enumerate a List With Index and Value
Loopsenumerate()
Python
Easy
74%
5.8K
Zip Two Lists Into Pairs
Loopszip()
Python
Easy
89%
6K
Repeat String N Times Using a Loop
Loopsfor loop
Python
Easy
82%
6.7K
Check Palindrome Using a Loop
Loopswhile loop
Python
Easy
74%
7.7K
Prime Number Checker Using a Loop
Loopsfor looploop-else
Python
Medium
55%
4.3K
Fibonacci Sequence via Loop
Loopsfor loopaccumulator
Python
Medium
61%
4.9K
Nested Loop Multiplication Grid
Loopsnested loops
Python
Medium
51%
3.2K
Print a Right-Angled Star Pyramid
Loopsnested loopspattern printing
Python
Medium
57%
6.9K
Loop-Else: Search for a Target Value
Loopsloop-elsefor loop
Python
Medium
64%
5.2K
Break/Continue Puzzle: Skip Multiples
Loopsbreak/continue
Python
Medium
62%
2.8K
Count Frequency of Each Character
Loopsfor loopaccumulator
Python
Medium
55%
7.6K
While Loop Input Validation Simulator
Loopswhile loop
Python
Medium
48%
3K
Sum of Even and Odd Numbers Separately
Loopsfor loopaccumulator
Python
Medium
64%
5.9K
GCD Using a While Loop
Loopswhile loop
Python
Medium
55%
4.3K
Print a Diamond Pattern With Nested Loops
Loopsnested loopspattern printing
Python
Medium
64%
5.1K
Digit Reversal and Palindrome Number Check
Loopswhile loop
Python
Medium
63%
6.7K
Shift Schedule Rotation Printer
Loopsfor loopBusiness Logic
Python
Medium
55%
3.5K
Running Total With Threshold Stop
Loopswhile loopbreak
Python
Medium
52%
5.9K
Pascal's Triangle Using Nested Loops
Loopsnested loopsaccumulator
Python
Hard
32%
6.5K
Prime Numbers Up to N (Sieve With Loops)
Loopsnested loops
Python
Hard
32%
6.8K
Matrix Transpose Using Nested Loops
Loopsnested loops
Python
Hard
33%
5.2K
Spiral Number Grid Printer
Loopsnested loopswhile loop
Python
Hard
35%
5K
Collatz Sequence Length Counter
Loopswhile loop
Python
Hard
39%
4.8K
Number Pattern: Floyd's Triangle Variant
Loopsnested loopspattern printing
Python
Hard
38%
7K
Perfect Number Finder in a Range
Loopsnested loops
Python
Hard
34%
3.4K
Greet With a Default Greeting
Functionsdefault arguments
Python
Easy
86%
9.1K
Rectangle Area and Perimeter Together
Functionsmultiple return values
Python
Easy
77%
6.8K
Sum Any Number of Scores
Functions*args
Python
Easy
82%
8K
Build a User Profile From Keyword Arguments
Functions**kwargs
Python
Easy
85%
9.7K
Order Summary With Mixed Arguments
Functions*args and **kwargs
Python
Medium
50%
6K
Keyword-Only Shipping Quote
Functionskeyword-only arguments
Python
Medium
51%
7.8K
Average of a Variable Number of Numbers
Functions*args
Python
Easy
83%
9.3K
Counter Factory Using a Closure
Functionsclosures
Python
Hard
31%
4.2K
Global Request Counter
Functionsglobal keyword
Python
Medium
49%
5.3K
Apply a Discount Strategy Function
Functionsfirst-class functions
Python
Medium
53%
3.5K
Operation Dispatch Table
Functionsfunctions in a dict
Python
Medium
50%
5K
Fix the Mutable Default Argument Bug
Functionsmutable default arguments
Python
Medium
46%
6.5K
Power Function With Type Hints
Functionstype hints
Python
Easy
84%
6K
Temperature Converter With a Proper Docstring
Functionsdocstrings
Python
Easy
73%
8.8K
Unpack Coordinates Into a Distance Function
Functionsargument unpacking
Python
Medium
61%
4.2K
Validate a Positive Integer Input
Functionsinput validation
Python
Easy
76%
5.2K
Curry-Lite: A Function That Returns an Adder
Functionsclosures
Python
Hard
25%
1.3K
Check Whether a String Is a Palindrome
Functionsreturn values
Python
Easy
78%
7.1K
Apply a Function N Times
Functionshigher-order functions
Python
Medium
46%
5.1K
Compose Two Functions
Functionsfirst-class functions
Python
Medium
60%
7.7K
Local Variable Shadowing a Global One
Functionsvariable scope
Python
Medium
51%
7.9K
Positional-Only Parameters for a Fast Path
Functionspositional-only parameters
Python
Medium
47%
7.3K
Retry Wrapper Built by Hand
Functionshigher-order functionsclosures
Python
Hard
33%
2.9K
Pure Function to Total a Cart (No Side Effects)
Functionspure functions
Python
Easy
85%
7.9K
Impure Function That Logs to a Shared List
Functionspure vs impure functions
Python
Easy
77%
8.4K
Grade Classifier With Multiple Return Points
Functionsreturn values
Python
Easy
77%
5.9K
Password Strength Checker with Keyword Rules
Functionsinput validation
Python
Medium
47%
3.3K
Nested Helper Function for Tax Brackets
Functionsnested functions
Python
Medium
48%
5.8K
Function Registry for a Mini Plugin System
Functionsfirst-class functions
Python
Hard
25%
6.6K
Demonstrate Default Arguments Are Evaluated Once
Functionsdefault argumentsscope
Python
Hard
31%
6.6K
Safe Divide With a Fallback Value
Functionsdefault arguments
Python
Easy
79%
5.4K
Word Frequency Counter Utility
Functionsutility functions
Python
Medium
57%
6.2K
Function Factory: Choose an Operation at Creation Time
Functionsclosuresfirst-class functions
Python
Hard
36%
6.8K
Rectangle-Or-Square Constructor With Smart Defaults
Functionsdefault arguments
Python
Medium
49%
3.3K
Build a Text Transform Pipeline From a List of Functions
Functionshigher-order functions
Python
Hard
26%
4.9K
BMI Calculator That Returns Value and Category
Functionsmultiple return values
Python
Easy
73%
5.2K
Running Average Tracker With Nonlocal State
Functionsnonlocalclosures
Python
Hard
24%
6.5K
Keyword Argument Overriding a Positional Default
Functionskeyword arguments
Python
Easy
79%
4.8K
Utility Function: Common Elements Between Two Lists
Functionsutility functions
Python
Easy
88%
5.5K
Tiered Loyalty Discount Calculator
Functionsdefault arguments
Python
Medium
58%
5.8K
Factorial the Recursive Way
RecursionMath
Python
Easy
88%
7.6K
Nth Fibonacci Number, Recursively
RecursionMath
Python
Easy
88%
8.5K
Sum of Digits via Recursion
RecursionMath
Python
Easy
76%
7.4K
Integer Power Function (Recursive)
RecursionMath
Python
Easy
81%
8.5K
Greatest Common Divisor via Euclidean Recursion
RecursionMath
Python
Medium
45%
3.3K
Sum a List Recursively
RecursionLists
Python
Easy
85%
9.2K
Reverse a String Using Recursion
RecursionStrings
Python
Easy
75%
6.2K
Count Paths in a Grid (Recursive)
RecursionTree-Like Recursion
Python
Hard
34%
1.9K
Sum 1..N — Accumulator vs Plain Recursion
RecursionFunctions
Python
Medium
49%
6.2K
Even/Odd Check via Mutual Recursion
RecursionFunctions
Python
Medium
61%
3.2K
Fibonacci with a Memo Dictionary
RecursionOptimization
Python
Hard
34%
3K
Binary Search, Recursively
RecursionSearching
Python
Medium
62%
6.3K
Flatten an Arbitrarily Nested List
RecursionLists
Python
Medium
57%
3.3K
Palindrome Check via Recursion
RecursionStrings
Python
Easy
86%
10K
Countdown Timer with a Safe Recursion Base Case
RecursionError Handling
Python
Hard
29%
4.8K
Pack and Unpack a Sensor Reading
TuplesVariables & Data Types
Python
Easy
77%
5.2K
A Tuple's Shell Is Immutable, Its Contents May Not Be
TuplesMutability
Python
Medium
53%
2.6K
Tuple or List? Pick the Right Tool
TuplesLists
Python
Easy
79%
9.8K
Employee Records with namedtuple
Tuplescollections.namedtuple
Python
Medium
59%
4.5K
Caching Grid Computations with Tuple Keys
TuplesDictionaries
Python
Hard
34%
5.4K
Rotate Three Variables in One Line
TuplesVariables & Data Types
Python
Easy
73%
9.4K
Split a Full Name and Return Multiple Values
TuplesStrings
Python
Easy
77%
8.9K
Slice Fields Out of a Fixed-Width Record Tuple
TuplesSlicing
Python
Easy
74%
5.2K
Sort Player Scores by Points
TuplesSorting
Python
Medium
53%
3.9K
Sum Distances in a Nested Tuple of Points
TuplesNested Data
Python
Medium
50%
8.5K
Build a Padded Tuple with + and *
TuplesOperators
Python
Medium
54%
2.9K
Zip Three Parallel Lists into Tuple Records
Tupleszip()
Python
Easy
80%
8.1K
Compare Version Numbers as Tuples
TuplesComparison
Python
Medium
54%
3.1K
Grab Head, Tail and Middle with Star-Unpacking
TuplesUnpacking
Python
Hard
38%
4.7K
Round-Trip Between Tuple, List and Set
TuplesSets
Python
Hard
32%
7K
Reverse a String with Slicing
StringsSlicing
Python
Easy
82%
5.1K
Palindrome Check via Slicing
StringsSlicing
Python
Easy
84%
7.8K
Swap the Case of a Sentence
StringsCase Conversion
Python
Easy
86%
9.6K
Capitalize Every Word (Title Case)
StringsCase Conversion
Python
Easy
87%
6.1K
Trim Whitespace Three Ways
StringsWhitespace Handling
Python
Easy
79%
8.3K
Split and Rejoin a Sentence
Stringssplit/join
Python
Easy
85%
5.7K
Count Substring Occurrences
StringsSubstring Search
Python
Easy
88%
7K
Find and Replace a Word
Stringsreplace
Python
Easy
85%
6.2K
Locate a Substring's Position
StringsSubstring Search
Python
Easy
76%
4.8K
Filename Extension Checker
Stringsstartswith/endswith
Python
Easy
85%
6.3K
Repeat a Character to Build a Border
StringsRepetition
Python
Easy
85%
6.3K
Count Words in a Sentence
Stringssplit
Python
Easy
85%
6K
Find the Longest Word
Stringssplit
Python
Easy
85%
9.8K
Check If a String Is Pure ASCII
StringsEncoding Basics
Python
Easy
78%
8K
Extract Substrings with Slicing Tricks
StringsSlicing
Python
Easy
85%
9.4K
Tally Vowels and Consonants Separately
StringsCharacter Frequency
Python
Easy
82%
6.7K
Add Thousand Separators to a Number String
StringsString Building
Python
Easy
75%
7K
Prove Strings Are Immutable
StringsImmutability
Python
Easy
87%
5.6K
Anagram Checker
StringsAnagrams
Python
Medium
52%
8.3K
Most Frequent Character
StringsCharacter Frequency
Python
Medium
45%
3K
Build an Invoice Line with f-strings
StringsString Formatting
Python
Medium
58%
7K
Old-Style % String Formatting
StringsString Formatting
Python
Medium
60%
3.4K
Align and Pad Columns with format()
StringsString Formatting
Python
Medium
54%
4.9K
Build a Large String Efficiently
StringsString Building
Python
Medium
49%
6.5K
Normalize Internal Whitespace
StringsWhitespace Handling
Python
Medium
46%
8.3K
Manual Substring Search (No find())
StringsSubstring Search
Python
Medium
52%
3.6K
Shift Characters with ord/chr
StringsEncoding Basics
Python
Medium
48%
6.5K
String Builder Pattern with a List
StringsString Building
Python
Medium
52%
7K
Longest Common Prefix
StringsSubstring Search
Python
Medium
49%
8.2K
Run-Length Encode a String
StringsString Compression
Python
Medium
64%
3K
Run-Length Decode a String
StringsString Compression
Python
Medium
60%
5.5K
Validate a Python Identifier
StringsValidation
Python
Medium
55%
7.2K
Fill In Template Placeholders
StringsTemplates
Python
Medium
54%
7.8K
Remove Duplicate Characters, Keep Order
StringsDeduplication
Python
Medium
46%
2.5K
Strip Unwanted Characters from Input
StringsSanitization
Python
Medium
55%
6K
Generate a URL Slug from a Title
StringsBusiness Logic
Python
Medium
54%
5.7K
Caesar Cipher Encryption
StringsCiphers
Python
Hard
27%
3.6K
Check If One String Is a Rotation of Another
StringsSubstring Search
Python
Hard
35%
5.1K
Validate a Username Manually
StringsValidation
Python
Hard
30%
1.3K
Parse a Log Line Without Regex
StringsParsing
Python
Hard
39%
1.2K
Count Palindromic Substrings
StringsPalindromes
Python
Hard
31%
6.8K
Longest Palindromic Substring
StringsPalindromes
Python
Hard
31%
4.1K
One Edit Away Check
StringsComparison
Python
Hard
29%
1.5K
Group Anagrams
StringsAnagrams
Python
Hard
34%
6.9K
First Non-Repeating Character
StringsCharacter Frequency
Python
Hard
39%
6.4K
Build a List From a Range
ListsCreation
Python
Easy
88%
4.7K
First and Last Element
ListsIndexing
Python
Easy
88%
9K
Slice the Middle Section
ListsSlicing
Python
Easy
88%
6.2K
Reverse a List With Step Slicing
ListsSlicing
Python
Easy
83%
9.9K
Append vs Extend
ListsMutation
Python
Easy
87%
9.2K
Insert a Value at a Position
ListsMutation
Python
Easy
73%
6.7K
Remove the First Occurrence
ListsMutation
Python
Easy
85%
5.4K
Pop an Element and Report Both Parts
ListsMutation
Python
Easy
86%
6.3K
sort() In-Place vs sorted() New List
ListsSorting
Python
Easy
82%
5.6K
Sort Strings by Length
ListsSorting
Python
Easy
75%
4.6K
Sort a List of Tuples by Second Value
ListsSorting
Python
Medium
48%
4.9K
Concatenate and Repeat Lists
ListsOperators
Python
Easy
79%
8.8K
Flatten a 2D List
ListsNested Lists
Python
Medium
56%
8K
Flatten a Deeply Nested List
ListsRecursionNested Lists
Python
Hard
39%
6.2K
Min, Max, Sum and Average in One Pass
ListsAggregation
Python
Easy
84%
7.2K
Remove Duplicates While Preserving Order
ListsDeduplication
Python
Medium
62%
8.5K
Find the Index of a Value
ListsSearching
Python
Easy
82%
4.3K
Split a List Into Fixed-Size Chunks
ListsSlicing
Python
Medium
51%
3.4K
Rotate a List to the Left
ListsSlicing
Python
Medium
45%
3.7K
Rotate a List to the Right
ListsSlicing
Python
Medium
60%
7.3K
Zip Two Lists Into Pairs and a Dict
ListsZipping
Python
Easy
86%
7K
Merge Two Sorted Leaderboards
ListsTwo Pointers
Python
Hard
24%
1.2K
Move All Zeros to the End
ListsTwo Pointers
Python
Medium
64%
3.2K
Pair Sum in a Sorted List
ListsTwo Pointers
Python
Medium
47%
8.4K
Shallow Copy vs Reference Assignment
ListsCopying
Python
Medium
47%
6.2K
List Equality vs Identity
ListsIdentity
Python
Easy
76%
9.7K
Transpose a Matrix
ListsMatrixNested Lists
Python
Medium
61%
3.7K
Rotate a Matrix 90 Degrees Clockwise
ListsMatrixNested Lists
Python
Hard
35%
3.2K
Find the Second Largest Element
ListsSearching
Python
Medium
47%
8K
Frequency Count Using Only Lists
ListsFrequency Counting
Python
Medium
61%
7.6K
Simulate a Stack With a List
ListsStack
Python
Easy
83%
6K
Sum All Numbers in a Nested List
ListsRecursionNested Lists
Python
Medium
48%
5.1K
In-Place Doubling vs New List Doubling
ListsMutation
Python
Medium
51%
5.3K
Extract a Field From a List of Dicts
ListsDicts
Python
Easy
85%
7.4K
Row and Column Sums of a Grid
ListsMatrixNested Lists
Python
Medium
64%
4.1K
Insert a Value Into a Sorted List
ListsSearching
Python
Medium
54%
5.8K
Common and Unique Elements Between Two Lists
ListsComparison
Python
Medium
64%
3.4K
Maximum Sum of a Fixed-Size Window
ListsSliding Window
Python
Hard
38%
2.5K
Collapse Consecutive Duplicates
ListsDeduplication
Python
Medium
61%
6.8K
Weighted Average From a List of Tuples
ListsBusiness Logic
Python
Medium
61%
2.6K
Find the Missing Number in a Range
ListsMath
Python
Medium
59%
4.9K
Partition a List Around a Pivot
ListsTwo Pointers
Python
Hard
38%
3K
Top N Elements Without Full Sort
ListsSelection
Python
Hard
26%
3K
Extract the Boundary of a Matrix
ListsMatrixNested Lists
Python
Medium
64%
5.5K
Compare Two Shopping Cart Totals
ListsBusiness Logic
Python
Easy
73%
8.1K
Build a Student Record
Dictionariescreation
Python
Easy
80%
9.4K
Safe Get with a Default
Dictionariesget()
Python
Easy
81%
7.8K
List All Keys and Values
Dictionarieskeys()/values()
Python
Easy
88%
9.5K
Check Key Membership
Dictionariesmembership
Python
Easy
79%
8.5K
Remove a Key Safely
Dictionariespop()
Python
Easy
85%
7.4K
Merge Two Config Dicts
Dictionariesmerging
Python
Easy
75%
7K
Nested Address Lookup
Dictionariesnested dicts
Python
Medium
62%
5.4K
Word Frequency Counter
Dictionariescounting
Python
Easy
74%
4.8K
Invert a Dictionary
Dictionariesinversion
Python
Medium
50%
4.6K
Sort a Dict by Value
Dictionariessorting
Python
Medium
64%
7K
Group Words by First Letter
Dictionariesgrouping
Python
Medium
52%
4.3K
Tally Votes with defaultdict
Dictionariesdefaultdict
Python
Easy
77%
8.5K
Most Common Character
DictionariesCounter
Python
Easy
87%
8.8K
Iterate and Transform Items
Dictionariesiterating items()
Python
Easy
78%
5.7K
Are Two Dicts Equal?
Dictionariesequality
Python
Easy
74%
8.3K
Shallow vs Deep Copy of Nested Dicts
Dictionariescopying
Python
Medium
64%
4.1K
Build a Dict from Two Parallel Lists
Dictionarieszip()
Python
Easy
76%
7.3K
Nested Order Total Traversal
Dictionariesnested traversal
Python
Medium
54%
7.2K
Fibonacci with Dict Memoization
Dictionariesmemoization
Python
Medium
54%
5.4K
Least Frequent Element
Dictionariesfrequency analysis
Python
Medium
62%
7.6K
Key Exists vs Truthy Value
Dictionariesexistence vs falsy values
Python
Easy
83%
9.5K
Merge Inventories with Conflict Resolution
Dictionariesmergingconflict resolution
Python
Medium
62%
3.7K
Leaderboard Top Scorer
Dictionariesleaderboard
Python
Easy
72%
5.2K
Multi-Level Scoreboard Update
Dictionariesnested dictsleaderboard
Python
Hard
29%
3.3K
Cache an Expensive Lookup
Dictionariescaching
Python
Medium
56%
3.5K
Group Transactions by Category
Dictionariesgroupingbusiness logic
Python
Medium
59%
6.7K
First Non-Repeating Character
Dictionariesfrequency
Python
Medium
55%
5.1K
Compare Two Inventory Snapshots
Dictionariescomparisonbusiness logic
Python
Hard
30%
3.8K
Two Sum Using a Dict Lookup
Dictionarieslookup tableclassic
Python
Medium
55%
7.3K
Group Anagrams
Dictionariesgroupingstrings
Python
Hard
29%
6K
Update a Deeply Nested Dict Safely
Dictionariesnested dictssetdefault
Python
Hard
39%
4K
Find Keys Common to All Dicts
Dictionariesset operations
Python
Medium
47%
6.6K
Bucket Support Tickets by Priority
Dictionariesbusiness logicgrouping
Python
Easy
78%
4.3K
Coupon Redemption Tally with Cap Check
Dictionariesbusiness logicCounter
Python
Hard
27%
2.4K
Symmetric Difference of Two Dicts’ Keys
Dictionariesset operations
Python
Medium
61%
5.7K
Deduplicate a Mailing List
Setsdeduplication
Python
Easy
77%
5.9K
Safe Tag Manager
Setsadd/discard
Python
Easy
73%
6.7K
Skills Both Candidates Share
Setsintersection
Python
Easy
86%
4.8K
What Changed Between Two Snapshots
Setssymmetric difference
Python
Medium
50%
8.2K
Role Permission Checker
Setssubset/superset
Python
Medium
50%
5.9K
Count Unique Meal Combos
Setsfrozenset
Python
Hard
32%
7.1K
Find the Missing Invoice IDs
Setsdifference
Python
Medium
59%
8.2K
Pangram Detector
Setsmembership
Python
Easy
76%
9.8K
No Double-Booked Employees
Setsisdisjoint
Python
Easy
72%
5.1K
Customers in Exactly One Campaign
Setsset algebra
Python
Medium
46%
8.1K
Merge Watchlists In Place
Setsin-place update
Python
Medium
48%
6.7K
Letters Unique to the First Word
Setsdifference
Python
Easy
74%
8.4K
First Repeated Product Scan
Setsseen-tracking
Python
Medium
64%
5.7K
Drain the Raffle Drum
Setspop
Python
Easy
86%
9.3K
Does the Course Cover the Syllabus?
Setssuperset
Python
Medium
59%
8.2K
Visitors Active on All Three Days
Setsmulti-set intersection
Python
Medium
59%
6K
Fast Stopword Filter
Setslookup performance
Python
Easy
72%
4.5K
Detect Duplicate Matchups
Setsfrozensetdeduplication
Python
Hard
30%
2.3K
Longest Consecutive Badge Streak
Setsalgorithm
Python
Hard
34%
1.7K
Same Inventory, Different Receipts
Setsequality
Python
Easy
82%
6.9K
Squares of the Even Numbers
List Comprehensionsfilter + map
Python
Easy
82%
5.2K
Pass/Fail Labels in One Line
List Comprehensionsconditional expression
Python
Easy
87%
8.6K
Flatten the Seating Chart
List Comprehensionsnested loops
Python
Medium
46%
4.9K
Every Size-Color Variant
List Comprehensionscartesian product
Python
Medium
52%
3.8K
Build a Price Lookup Dict
List Comprehensionsdict comprehension
Python
Easy
72%
6.3K
Distinct Email Domains
List Comprehensionsset comprehension
Python
Easy
88%
5.9K
Flag Every Third Row
List Comprehensionsenumerate
Python
Medium
53%
4.1K
Apply Per-Item Tax Rates
List Comprehensionszip
Python
Medium
63%
3.8K
Clean Up Messy CSV Cells
List Comprehensionsstring cleanup
Python
Medium
57%
3.1K
Transpose a Grade Matrix
List Comprehensionsnested comprehension
Python
Hard
39%
2.2K
In-Stock Product Names
List Comprehensionslist of dicts
Python
Easy
85%
7.7K
Consecutive Reading Pairs
List Comprehensionssliding window
Python
Medium
47%
6.2K
Generate Employee Initials
List Comprehensionsstring split
Python
Easy
77%
8.5K
Multiplication Table Rows
List Comprehensionsnested build
Python
Easy
84%
5.8K
Invert a Country-Code Dict
List Comprehensionsdict comprehension
Python
Medium
54%
6.4K
Filter Valid Coupon Codes
List Comprehensionsmultiple conditions
Python
Medium
60%
7.9K
Podium Finishers with Medals
List Comprehensionszip + slicing
Python
Medium
49%
7.5K
Extract Numeric Ticket IDs
List Comprehensionsstring parsing
Python
Hard
29%
4.4K
Heatmap Cell Symbols
List Comprehensionsnested conditional expression
Python
Hard
26%
1.9K
Word Length Frequency Report
List Comprehensionsdict comprehensionaggregation
Python
Hard
33%
6.1K
Sort Products by Price
Lambda & Functionalsorted key
Python
Easy
74%
6.9K
Convert Temperatures with map()
Lambda & Functionalmap
Python
Easy
82%
8.8K
Filter Voting-Age Users
Lambda & Functionalfilter
Python
Easy
78%
6.7K
Cart Total with reduce()
Lambda & Functionalreduce
Python
Medium
63%
5.6K
Best-Rated Restaurant
Lambda & Functionalmax with key
Python
Easy
82%
5.2K
Sort by Grade, Then Name
Lambda & Functionalmulti-key sort
Python
Medium
49%
7.8K
Element-wise Order Totals
Lambda & Functionalmap multiple iterables
Python
Medium
48%
8K
Drop the Failed Sensor Reads
Lambda & Functionalfilter None
Python
Easy
78%
8.1K
Peak Traffic via reduce()
Lambda & Functionalreduce
Python
Medium
64%
5K
Calculator Dispatch Table
Lambda & Functionaldict of lambdas
Python
Medium
46%
6.3K
Fleet Health Checks with any() and all()
Lambda & Functionalany/all
Python
Medium
55%
4.9K
Nearest Delivery Hub
Lambda & Functionalmin with key
Python
Medium
49%
8.2K
Compose Two Transformations
Lambda & Functionalfunction composition
Python
Hard
24%
5.1K
Flatten with reduce()
Lambda & Functionalreduce
Python
Hard
29%
2.9K
Preset Shipping Calculators with partial()
Lambda & Functionalfunctools.partial
Python
Hard
24%
5.6K
Leaderboard from a Score Dict
Lambda & Functionalsorting dict items
Python
Medium
52%
6.7K
Chained map-filter Salary Pipeline
Lambda & Functionalmap + filter chain
Python
Medium
59%
3.9K
The Late-Binding Lambda Trap
Lambda & Functionalclosureslate binding
Python
Hard
34%
2.6K
Apply a Function over Argument Tuples
Lambda & Functionalargument unpacking
Python
Hard
25%
2.8K
Two-Pass Stable Sort Trick
Lambda & Functionalstable sort
Python
Hard
28%
6K
Count the Lines in a Log File
File Handlingreading
Python
Easy
78%
5.6K
Write a Daily Report File
File Handlingwriting
Python
Easy
72%
7.8K
Append to an Audit Trail
File Handlingappend mode
Python
Easy
85%
7.6K
Read the Non-Blank Lines
File Handlingcleanup
Python
Easy
78%
9.7K
Read a File, or a Default
File Handlingexistence check
Python
Easy
84%
9.5K
Total a Sales CSV by Hand
File Handlingcsv parsing
Python
Medium
50%
7.8K
Mini-Grep: Matching Lines with Numbers
File Handlingsearch
Python
Medium
48%
3.1K
Copy a File Without Comment Lines
File Handlingread + write
Python
Medium
57%
6.1K
Implement tail -n
File Handlingtail
Python
Medium
57%
4.5K
Most Frequent Word in a Document
File Handlingaggregation
Python
Medium
49%
8.1K
Merge Two Sorted Roster Files
File Handlingmerging
Python
Hard
33%
4.6K
Checksum a Large File in Chunks
File Handlingbinary modechunked reading
Python
Hard
25%
6.8K
Preview, Rewind, Re-read
File Handlingseek/tell
Python
Hard
25%
2.2K
Parse a key=value Config File
File Handlingparsing
Python
Medium
54%
7.8K
Deduplicate a File In Place
File Handlingdedup + rewrite
Python
Medium
50%
5.7K
Text File Statistics
File Handlingcounting
Python
Easy
75%
9.4K
Rotate a Log File by Size
File Handlingos modulerotation
Python
Hard
31%
1.3K
List All Text Files in a Folder
File Handlingos.listdir
Python
Easy
77%
8.1K
Crash-Safe File Update
File Handlingatomic write
Python
Hard
38%
1.6K
Add Line Numbers to a Script
File Handlingtransform
Python
Easy
85%
7.2K
Division That Never Crashes
Exception Handlingtry/except
Python
Easy
88%
4.1K
Robust Integer Parser
Exception HandlingValueError
Python
Easy
81%
5.7K
Diagnose the Failure Type
Exception Handlingmultiple except
Python
Medium
48%
2.5K
Always Release the Lock
Exception Handlingfinally
Python
Medium
53%
3.5K
The Forgotten else of try
Exception Handlingtry/else
Python
Medium
50%
4.4K
Raise on Invalid Discount
Exception Handlingraise
Python
Easy
82%
8.9K
Design an InsufficientFunds Error
Exception Handlingcustom exceptions
Python
Medium
63%
3.2K
Wrap and Chain the Real Cause
Exception Handlingraise from
Python
Hard
32%
4K
Retry a Flaky Operation
Exception Handlingretry loop
Python
Hard
30%
3.6K
Collect Every Form Error
Exception Handlingvalidation aggregation
Python
Medium
57%
6.3K
Why Catch Order Matters
Exception Handlingexception hierarchy
Python
Hard
30%
2.4K
Build a with-Statement Timer
Exception Handlingcontext managers
Python
Hard
26%
5.4K
Guard Invariants with assert
Exception Handlingassert
Python
Easy
77%
7.2K
Best-Effort Cleanup
Exception Handlingsuppression
Python
Medium
45%
6K
Log, Then Re-raise Unchanged
Exception Handlingbare raise
Python
Medium
55%
7.5K
Keep Asking Until Valid
Exception Handlinginput loop
Python
Medium
48%
7.6K
Translate API Error Codes
Exception Handlingraising by lookup
Python
Medium
64%
6.5K
Commit or Roll Back
Exception Handlingtransaction pattern
Python
Hard
30%
3.2K
Read an Exception Message Safely
Exception Handlingexception object
Python
Easy
80%
5.8K
Process What You Can, Report the Rest
Exception Handlingpartial failure
Python
Medium
60%
4K
Circle Math with the math Module
Modules & Packagesmath
Python
Easy
78%
6.3K
Six-Digit OTP Generator
Modules & Packagesrandom
Python
Easy
79%
4.2K
Top-K Items via collections.Counter
Modules & Packagescollections
Python
Easy
87%
8.4K
Chunk an Iterable with itertools
Modules & Packagesitertools
Python
Medium
45%
7.6K
Portable Path Building
Modules & Packagesos.path
Python
Easy
79%
8.4K
Parse Command-Line Arguments
Modules & Packagessys.argv
Python
Medium
57%
4.9K
The __main__ Guard, Explained in Code
Modules & Packages__name__
Python
Easy
82%
6.1K
Days Since Signup
Modules & Packagesdatetime
Python
Easy
86%
6.4K
Group Employees by Department
Modules & Packagescollections.defaultdict
Python
Medium
53%
5.7K
Character Sets from the string Module
Modules & Packagesstring module
Python
Medium
48%
8.3K
Import Styles: Module vs from vs as
Modules & Packagesimport forms
Python
Easy
79%
7.2K
Grade Summary with the statistics Module
Modules & Packagesstatistics
Python
Easy
73%
5.7K
Design a Package Layout
Modules & Packagespackage structure
Python
Medium
51%
5K
Three Cheapest Fares with heapq
Modules & Packagesheapq
Python
Medium
61%
7.2K
Modules Are Singletons
Modules & Packagesimport caching
Python
Hard
39%
1.2K
Model a Library Book
OOPclass basics
Python
Easy
88%
6.3K
Store-Wide Tax, Item-Specific Price
OOPclass attributes
Python
Medium
64%
3.5K
__str__ vs __repr__
OOPdunder methods
Python
Medium
53%
3K
Encapsulated Bank Account
OOPencapsulation
Python
Medium
61%
6.8K
Vehicles That Specialize
OOPinheritance
Python
Easy
72%
4.9K
Extend, Don’t Replace, the Constructor
OOPsuper()
Python
Medium
53%
5.8K
One Loop, Many Shapes
OOPpolymorphism
Python
Medium
56%
6K
Alternate Constructor from a String
OOPclassmethod
Python
Medium
54%
6.5K
A Validator That Needs No self
OOPstaticmethod
Python
Easy
81%
5.1K
Value Equality for Money
OOP__eq__ and __hash__
Python
Hard
35%
4.3K
Make a Playlist Feel Like a List
OOP__len__ and __getitem__
Python
Medium
56%
5.6K
Overload + for 2D Vectors
OOPoperator overloading
Python
Medium
64%
5K
Temperature with a Guarded Setter
OOPproperty setter
Python
Medium
64%
8K
Count Your Instances
OOPclass state
Python
Easy
88%
5.3K
Force Subclasses to Implement pay()
OOPabstract base classes
Python
Hard
32%
6.6K
Invoice as a dataclass
OOPdataclasses
Python
Easy
79%
8.7K
An Engine the Car Owns
OOPcomposition
Python
Medium
58%
4.3K
Double Underscore Name Mangling
OOPname mangling
Python
Hard
32%
4K
Predict the Diamond MRO
OOPMROmultiple inheritance
Python
Hard
28%
4.6K
Objects You Can Call
OOP__call__
Python
Hard
27%
4.5K
Support the in Operator
OOP__contains__
Python
Easy
89%
6.7K
Sortable Software Versions
OOPcomparison dunders
Python
Hard
38%
3.2K
Lock Down Attributes with __slots__
OOP__slots__
Python
Hard
30%
3.9K
A Serialization Mixin
OOPmixins
Python
Hard
35%
2.3K
isinstance Respects Inheritance, type() Does Not
OOPisinstance
Python
Medium
62%
4.2K
A Shopping Cart Object
OOPstateful methods
Python
Easy
82%
6.6K
Override AND Reuse the Parent Logic
OOPoverride + super
Python
Medium
55%
5.7K
Mini Library Lending System
OOPmulti-class design
Python
Hard
30%
7K
Graceful Missing Attributes with __getattr__
OOP__getattr__
Python
Hard
29%
2.2K
Immutable Coordinates
OOPfrozen dataclass
Python
Medium
46%
6K
Swap Pricing Strategies at Runtime
OOPstrategy pattern
Python
Hard
32%
1.2K
Duck-Typed Notification Fan-out
OOPduck typing
Python
Medium
45%
5.7K
Order Status Observers
OOPobserver pattern
Python
Hard
32%
4.4K
Payroll Across a Class Hierarchy
OOPinheritance + polymorphism
Python
Medium
60%
7.7K
A Countdown You Can Iterate
OOP__iter__ and __next__
Python
Medium
56%
7.6K
Hand-Rolled vs dataclass Equality
OOPdataclass comparison
Python
Medium
49%
8.4K
Singleton via __new__
OOP__new__singleton
Python
Hard
25%
3.1K
Template Method for Reports
OOPtemplate method
Python
Hard
34%
3.5K
Deep-Copy an Object Graph
OOPcopying objects
Python
Hard
31%
3K
A Door With Legal Transitions Only
OOPstate modeling
Python
Medium
62%
6K
Parse an ISO Date String
Date & Timestrptime
Python
Easy
81%
8.9K
Format a Date for Humans
Date & Timestrftime
Python
Easy
78%
8.9K
Add Business Days to a Date
Date & Timetimedeltaweekday
Python
Hard
35%
5.3K
Exact Age in Years
Date & Timedate arithmetic
Python
Medium
62%
8K
Do Two Meetings Overlap?
Date & Timeinterval logic
Python
Medium
57%
8K
Seconds to H:MM:SS
Date & Timeduration formatting
Python
Easy
75%
5.2K
Last Day of Any Month
Date & Timecalendar math
Python
Medium
58%
7.9K
Between Epoch and datetime
Date & Timeunix timestamps
Python
Medium
59%
3K
Time Remaining, Nicely Worded
Date & Timetimedelta breakdown
Python
Medium
46%
8.4K
Logins per Weekday
Date & Timeaggregation
Python
Medium
63%
4.4K
Leap Year by the Full Rules
Date & Timeleap year
Python
Easy
72%
9.1K
Next Monday After a Date
Date & Timeweekday arithmetic
Python
Medium
60%
7.9K
Parse Dates in Mixed Formats
Date & Timemulti-format parsing
Python
Hard
27%
3.8K
Show a UTC Time in Another Zone
Date & Timetimezones
Python
Hard
30%
1.8K
Current Daily-Login Streak
Date & Timestreak logic
Python
Hard
26%
7K
Find All 10-Digit Phone Numbers
Regular Expressionsfindall
Python
Easy
87%
4.7K
Practical Email Validator
Regular Expressionsfullmatch
Python
Medium
57%
3.4K
Parse Log Lines with Groups
Regular Expressionsgroups
Python
Medium
52%
7.5K
Mask Card Numbers in Text
Regular Expressionssub
Python
Medium
50%
3K
Split on Any of Several Delimiters
Regular Expressionssplit
Python
Easy
81%
9.2K
Extract Hashtags
Regular Expressionsfindall
Python
Easy
83%
5.3K
Greedy vs Lazy: Strip Bold Tags
Regular Expressionslazy quantifiers
Python
Hard
31%
4.9K
Collapse Runs of Whitespace
Regular Expressionssub
Python
Easy
73%
6.2K
Password Rules via Lookaheads
Regular Expressionslookaheads
Python
Hard
28%
6.1K
Pull Rupee Amounts from Text
Regular Expressionsnumeric capture
Python
Medium
57%
7.6K
Count a Word, Not Its Substrings
Regular Expressionsword boundaries
Python
Medium
46%
8.2K
Rewrite Dates with Backreferences
Regular Expressionsbackreferences
Python
Medium
47%
3.5K
Compile Once, Scan Many
Regular Expressionsre.compile
Python
Medium
55%
6.4K
match vs search vs fullmatch
Regular Expressionsmatch/search semantics
Python
Easy
82%
8.3K
Slugify a Blog Title
Regular Expressionssub pipeline
Python
Medium
47%
2.8K
Parse a User Profile JSON
JSONloads
Python
Easy
80%
5.9K
Pretty-Print Config as JSON
JSONdumps options
Python
Easy
75%
7K
Safely Read a Nested JSON Path
JSONnested access
Python
Medium
48%
7.1K
Load, Update, Save Settings
JSONfile round-trip
Python
Medium
54%
7.1K
Survive Malformed JSON
JSONJSONDecodeError
Python
Easy
88%
5.8K
Filter a JSON Array of Orders
JSONarray processing
Python
Medium
63%
8K
JSON Types → Python Types
JSONtype mapping
Python
Easy
73%
10K
Flatten JSON to Dot-Keys
JSONflattening
Python
Hard
36%
6.9K
Serialize Dates with a default Hook
JSONcustom serialization
Python
Hard
27%
6.9K
Deep-Merge Two JSON Configs
JSONdeep merge
Python
Hard
30%
4.6K
Process a JSON-Lines Stream
JSONJSONL
Python
Medium
63%
5.6K
Redact Secrets Before Logging
JSONrecursive transform
Python
Medium
55%
3K
CSV Rows to JSON Records
JSONformat conversion
Python
Medium
56%
7.8K
Sort a JSON Catalog and Re-serialize
JSONparse-sort-dump
Python
Easy
85%
7.8K
Diff Two Flat JSON Objects
JSONcomparison
Python
Hard
24%
1.3K
Fetch and Parse a JSON API
APIsrequests.get
Python
Easy
77%
5.8K
Send Query Parameters Properly
APIsparams
Python
Easy
85%
9.7K
POST a JSON Payload
APIspost json
Python
Easy
73%
9.7K
Call a Protected Endpoint
APIsauth headers
Python
Medium
48%
7.6K
Never Hang: Timeouts and Fallbacks
APIstimeout
Python
Medium
53%
4.2K
Route on Status Codes
APIsstatus codes
Python
Easy
82%
5.1K
Walk Every Page of an API
APIspagination
Python
Hard
35%
5.4K
Retry with Exponential Backoff
APIsretries
Python
Hard
24%
6.5K
Reuse a Session for Many Calls
APIsrequests.Session
Python
Medium
63%
6.1K
Stream a Large Download to Disk
APIsstreaming
Python
Hard
39%
3.9K
Compose API URLs Without Bugs
APIsurl building
Python
Easy
82%
4.9K
Respect Rate-Limit Headers
APIsrate limiting
Python
Hard
33%
3.7K
A Testable Weather Client
APIsdependency injection
Python
Medium
62%
3.4K
Join Data from Two Endpoints
APIsdata joining
Python
Medium
61%
4.1K
Verify a Webhook Signature
APIswebhook security
Python
Hard
34%
5.3K
An Endless Fibonacci Stream
Iterators & Generatorsinfinite generator
Python
Easy
72%
7.5K
Yield Records in Batches
Iterators & Generatorsbatching
Python
Medium
47%
7.7K
Sum a Billion Squares Without a List
Iterators & Generatorsgenerator expression
Python
Easy
76%
5.6K
Lazily Yield Numbers from Lines
Iterators & Generatorslazy pipeline
Python
Medium
54%
6.6K
Streaming Running Average
Iterators & Generatorsstateful stream
Python
Medium
63%
4.2K
The One-Shot Generator Trap
Iterators & Generatorsexhaustion
Python
Medium
58%
8.4K
Flatten Deeply with yield from
Iterators & Generatorsyield from
Python
Hard
38%
3.1K
Yield the Change Between Readings
Iterators & Generatorspairwise
Python
Medium
62%
4K
A Generator You Can send() To
Iterators & Generatorssend
Python
Hard
38%
5.3K
Deduplicate an Infinite Stream
Iterators & Generatorsstateful filter
Python
Medium
48%
2.7K
Log Every Call
Decoratorsbasic decorator
Python
Easy
77%
9K
Time Any Function
Decoratorstiming
Python
Medium
45%
5.5K
Hand-Rolled Memoization
Decoratorscaching
Python
Medium
48%
6.7K
A Decorator That Takes Arguments
Decoratorsdecorator factory
Python
Hard
33%
5K
Reject Negative Arguments at the Door
Decoratorsvalidation
Python
Medium
63%
4.6K
Why functools.wraps Matters
Decoratorsfunctools.wraps
Python
Easy
75%
5.8K
Role-Gated Endpoints
Decoratorsauthorization
Python
Hard
31%
5K
Stacked Decorators Run Bottom-Up
Decoratorsstacking order
Python
Medium
60%
2.8K
A Wrapper That Counts Itself
Decoratorsfunction attributes
Python
Medium
63%
5.2K
Auto-Register Commands
Decoratorsregistry pattern
Python
Hard
28%
6.3K
GST Invoice Calculator
Business Logicbilling
Python
Easy
75%
4.7K
Tiered Sales Commission
Business Logictiered rates
Python
Medium
58%
6.5K
Loan EMI Calculator
Business Logicfinance
Python
Medium
49%
6.9K
Which SKUs Need Reordering?
Business Logicinventory
Python
Easy
79%
7.3K
Split a Bill Without Losing Paise
Business Logicmoney precision
Python
Hard
34%
6.8K
Ride Surge Pricing Engine
Business Logicdynamic pricing
Python
Medium
58%
5K
Loyalty Points with Expiry
Business LogicFIFO ledger
Python
Hard
26%
4.4K
Overtime Pay from Punch Logs
Business Logicpayroll
Python
Medium
46%
6.5K
Funnel Conversion Report
Business Logicmetrics
Python
Easy
87%
8.1K
Train Seats and the Waitlist
Business Logicallocation
Python
Medium
47%
7.8K
Price-Drop Alert Trigger
Business Logicthresholds
Python
Easy
82%
4.9K
CTC to Take-Home Breakdown
Business Logicpayroll
Python
Medium
58%
2.8K
Peak Hour from Reservations
Business Logicinterval counting
Python
Hard
30%
5.4K
Refund Eligibility Engine
Business Logicpolicy rules
Python
Medium
51%
5.5K
A/B Test Winner (Practical Rule)
Business Logicexperimentation
Python
Medium
45%
3.4K
Catch Duplicate Payments
Business Logicfraud detection
Python
Medium
62%
7.5K
Pack Orders into Delivery Boxes
Business Logicgreedy packing
Python
Hard
39%
3.4K
Prorated Plan Upgrade
Business Logicsubscription billing
Python
Medium
55%
2.9K
Compute an NPS Score
Business Logicsurvey metrics
Python
Easy
86%
5.6K
Is Every Hour Covered?
Business Logiccoverage check
Python
Medium
48%
8.2K
Expense Approval Router
Business Logicrouting rules
Python
Easy
80%
7.3K
Month-1 Retention by Cohort
Business Logiccohort analysis
Python
Hard
25%
2K
OTP Request Rate Limiter
Business Logicrate limiting
Python
Medium
56%
6.8K
Curve Exam Scores to 100
Business Logicnormalization
Python
Easy
79%
4.3K
Book a Room Without Conflicts
Business Logicbooking conflicts
Python
Medium
53%
6.8K
Convert Through Cross Rates
Business Logicgraph-lite
Python
Hard
26%
3.6K
Flag SLA Breaches
Business LogicSLA rules
Python
Easy
78%
6.2K
Feature Flags by Plan
Business Logicentitlements
Python
Easy
89%
4.9K
Delivery Partner Weekly Payout
Business Logicgig payouts
Python
Medium
61%
7.8K
Reconcile a Stock Ledger
Business Logicreconciliation
Python
Medium
51%
7.5K
Happy Hour Discount Windows
Business Logictime-based pricing
Python
Medium
46%
6.1K
Score Sales Leads
Business Logicscoring
Python
Medium
53%
2.6K
Make Change with Fewest Notes
Business Logicgreedy change
Python
Medium
55%
5.9K
Auto-Moderate Product Reviews
Business Logicmoderation rules
Python
Medium
58%
4.6K
Electricity Bill by Slabs
Business Logicslab billing
Python
Medium
57%
7.4K
Flash Sale Order Processor
Business Logicordered allocation
Python
Hard
25%
6.7K
KPI Dashboard Traffic Lights
Business Logicdashboards
Python
Easy
72%
5.6K
Merge Duplicate CRM Contacts
Business Logicdedup + merge
Python
Hard
38%
6.1K
Project Year-End Revenue
Business Logicforecasting
Python
Easy
77%
4.6K
Estimated Wait Time at Support
Business Logicqueueing
Python
Medium
55%
4.9K
Which Discounts Stack?
Business Logicpromotion rules
Python
Hard
30%
4.2K
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