Python
From the official Python website:
Python is a programming language that lets you work more quickly and integrate your systems more effectively. You can learn to use Python and see almost immediate gains in productivity and lower maintenance costs."
It is easy to create clean bug-free programs in Python due to the motto: "Errors should never pass silently." Python is an interpreter. Python source files (.py files) are typically compiled to an intermediate bytecode language (.pyc files) and executed by a Python Virtual Machine.
Notes
Some Python examples may deviate from idiomatic Python because they may be written to work in Python 3.X as well as Python 2.X environments. This includes doing things like:
- Using brackets in print statements/functions of one expression.
- Using zip and not izip; keys(), values(), items() and not their iter- forms.
- Checking for raw_input and setting raw_input to input if not found.
- Conditionally importing reduce if it is not found.
This style is not a requirement for Python code on RosettaGit, but it may be in use and should not necessarily be 'corrected' if found in examples.
The command line is often used in Python for short pieces of code, and so, again; examples showing such use are not incorrect and may be left.
See Also
Todo
Tasks
- 100 doors
- 15 Puzzle Game
- 15 puzzle solver
- 2048
- 24 game
- 24 game/Solve
- 4-rings or 4-squares puzzle
- 9 billion names of God the integer
- A* search algorithm
- A+B
- ABC Problem
- AKS test for primes
- AVL tree
- Abbreviations, automatic
- Abbreviations, easy
- Abbreviations, simple
- Abelian sandpile model
- Abstract type
- Abundant odd numbers
- Abundant, deficient and perfect number classifications
- Accumulator factory
- Ackermann function
- Active Directory/Connect
- Active Directory/Search for a user
- Active object
- Add a variable to a class instance at runtime
- Addition chains
- Address of a variable
- Align columns
- Aliquot sequence classifications
- Almost prime
- Amicable pairs
- Anagrams
- Anagrams/Deranged anagrams
- Angle difference between two bearings
- Angles (geometric), normalization and conversion
- Animate a pendulum
- Animation
- Anonymous recursion
- Anti-primes
- Append a record to the end of a text file
- Apply a callback to an array
- Apply a digital filter (direct form II transposed)
- Approximate Equality
- Arbitrary-precision integers (included)
- Archimedean spiral
- Arena storage pool
- Arithmetic coding/As a generalized change of radix
- Arithmetic evaluation
- Arithmetic-geometric mean
- Arithmetic-geometric mean/Calculate Pi
- Arithmetic/Complex
- Arithmetic/Integer
- Arithmetic/Rational
- Array concatenation
- Array length
- Arrays
- Aspect Oriented Programming
- Assertions
- Associative array/Creation
- Associative array/Iteration
- Atomic updates
- Attractive numbers
- Average loop length
- Averages/Arithmetic mean
- Averages/Mean angle
- Averages/Mean time of day
- Averages/Median
- Averages/Mode
- Averages/Pythagorean means
- Averages/Root mean square
- Averages/Simple moving average
- Babbage problem
- Bacon cipher
- Balanced brackets
- Balanced ternary
- Barnsley fern
- Base58Check encoding
- Base64 decode data
- Base64 encode data
- Bell numbers
- Benford's law
- Bernoulli numbers
- Best shuffle
- Bilinear interpolation
- Binary digits
- Binary search
- Binary strings
- Birthday problem
- Bitcoin/address validation
- Bitcoin/public point to address
- Bitmap/Bézier curves/Cubic
- Bitmap/Bézier curves/Quadratic
- Bitmap/Flood fill
- Bitmap/Histogram
- Bitmap/Midpoint circle algorithm
- Bitmap/PPM conversion through a pipe
- Bitmap/Read a PPM file
- Bitmap/Read an image through a pipe
- Bitmap/Write a PPM file
- Bitwise IO
- Bitwise operations
- Boolean values
- Box the compass
- Brace expansion
- Brazilian numbers
- Break OO privacy
- Bresenham's Line Algorithm
- Brownian tree
- Bulls and cows
- Bulls and cows/Player
- Burrows–Wheeler transform
- CRC-32
- CSV data manipulation
- CSV to HTML translation
- CUSIP
- Caesar cipher
- Calculating the value of e
- Calendar
- Call a foreign-language function
- Call a function
- Call a function in a shared library
- Call an object method
- Canny edge detector
- Card shuffles
- Carmichael 3 strong pseudoprimes
- Cartesian product of two or more lists
- Case-sensitivity of identifiers
- Casting out nines
- Catalan numbers
- Catalan numbers/Pascal's triangle
- Catamorphism
- Catmull–Clark subdivision surface
- Chaocipher
- Chaos game
- Character codes
- Chat server
- Check Machin-like formulas
- Check input device is a terminal
- Check output device is a terminal
- Check that file exists
- Checkpoint synchronization
- Chemical Calculator
- Cheryl's Birthday
- Chess player
- Chinese remainder theorem
- Chinese zodiac
- Cholesky decomposition
- Chowla numbers
- Church Numerals
- Cipolla's algorithm
- Circles of given radius through two points
- Classes
- Closest-pair problem
- Closures/Value capture
- Code segment unload
- Collections
- Color of a screen pixel
- Color quantization
- Color wheel
- Colour bars/Display
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Combinations
- Combinations and permutations
- Combinations with repetitions
- Comma quibbling
- Command-line arguments
- Commatizing numbers
- Comments
- Compare a list of strings
- Compare sorting algorithms' performance
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Compound data type
- Concurrent computing
- Conditional structures
- Conjugate transpose
- Constrained random points on a circle
- Continued fraction
- Continued fraction/Arithmetic/Construct from rational number
- Convert decimal number to rational
- Convert seconds to compound duration
- Convex hull
- Copy a string
- Copy stdin to stdout
- Count in factors
- Count in octal
- Count occurrences of a substring
- Count the coins
- Cramer's rule
- Create a file
- Create a file on magnetic tape
- Create a two-dimensional array at runtime
- Create an HTML table
- Create an object/Native demonstration
- Cuban primes
- Cumulative standard deviation
- Currency
- Currying
- Cut a rectangle
- Damm algorithm
- Data Encryption Standard
- Date format
- Date manipulation
- Day of the week
- Days between dates
- De Bruijn sequences
- Decimal floating point number to binary
- Decision tables
- Deconvolution/1D
- Deconvolution/2D+
- Deepcopy
- Define a primitive data type
- Delegates
- Delete a file
- Deming's Funnel
- Department Numbers
- Detect division by zero
- Determinant and permanent
- Determine if a string is numeric
- Determine if only one instance is running
- Determine if two triangles overlap
- Dice game probabilities
- Digital root
- Digital root/Multiplicative digital root
- Dijkstra's algorithm
- Dinesman's multiple-dwelling problem
- Dining philosophers
- Discordian date
- Display a linear combination
- Distributed programming
- Diversity prediction theorem
- Documentation
- Dot product
- Doubly-linked list/Definition
- Doubly-linked list/Element definition
- Doubly-linked list/Element insertion
- Doubly-linked list/Traversal
- Dragon curve
- Draw a clock
- Draw a cuboid
- Draw a pixel
- Draw a rotating cube
- Draw a sphere
- Dutch national flag problem
- Dynamic variable names
- EKG sequence convergence
- Eban numbers
- Echo server
- Eertree
- Egyptian division
- Egyptian fractions
- Element-wise operations
- Elementary cellular automaton
- Elementary cellular automaton/Infinite length
- Elementary cellular automaton/Random Number Generator
- Elliptic curve arithmetic
- Emirp primes
- Empty directory
- Empty program
- Empty string
- Enforced immutability
- Entropy
- Entropy/Narcissist
- Enumerations
- Environment variables
- Equilibrium index
- Ethiopian multiplication
- Euler method
- Euler's identity
- Euler's sum of powers conjecture
- Evaluate binomial coefficients
- Even or odd
- Events
- Evolutionary algorithm
- Exceptions
- Exceptions/Catch an exception thrown in a nested call
- Executable library
- Execute Brainfuck
- Execute HQ9+
- Execute SNUSP
- Execute a Markov algorithm
- Execute a system command
- Exponentiation operator
- Exponentiation order
- Extend your language
- External sort
- Extract file extension
- Extreme floating point values
- FASTA format
- FTP
- Factorial
- Factorial base numbers indexing permutations of a collection
- Factors of a Mersenne number
- Factors of an integer
- Farey sequence
- Fast Fourier transform
- Faulhaber's triangle
- Feigenbaum constant calculation
- Fermat numbers
- Fibonacci heap
- Fibonacci n-step number sequences
- Fibonacci sequence
- Fibonacci word
- Fibonacci word/fractal
- File input and output
- Filter
- Find common directory path
- Find duplicate files
- Find first and last set bit of a long integer
- Find largest left truncatable prime in a given base
- Find limit of recursion
- Find the intersection of a line with a plane
- Find the intersection of two lines
- Find the last Sunday of each month
- Find the missing permutation
- First class environments
- First perfect square in base N with N unique digits
- First-class functions
- First-class functions/Use numbers analogously
- Five weekends
- Fivenum
- Fixed length records
- FizzBuzz
- Flatten a list
- Flipping bits game
- Flow-control structures
- Floyd's triangle
- Floyd-Warshall algorithm
- Forest fire
- Fork
- Formal power series
- Formatted numeric output
- Forward difference
- Four bit adder
- Four is magic
- Fractal tree
- Fractran
- Free polyominoes enumeration
- Function composition
- Function definition
- Function frequency
- Functional coverage tree
- Fusc sequence
- GUI component interaction
- GUI enabling/disabling of controls
- GUI/Maximum window dimensions
- Galton box animation
- Gamma function
- Gaussian elimination
- General FizzBuzz
- Generate Chess960 starting position
- Generate lower case ASCII alphabet
- Generate random chess position
- Generator/Exponential
- Generic swap
- Geometric algebra
- Get system command output
- Globally replace text in several files
- Go Fish
- Gray code
- Grayscale image
- Greatest common divisor
- Greatest element of a list
- Greatest subsequential sum
- Greyscale bars/Display
- Guess the number
- Guess the number/With feedback
- Guess the number/With feedback (player)
- HTTP
- HTTPS
- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Hailstone sequence
- Hamming numbers
- Handle a signal
- Happy numbers
- Harshad or Niven series
- Hash from two arrays
- Hash join
- Haversine formula
- Hello world!
- Hello world/Graphical
- Hello world/Line printer
- Hello world/Newbie
- Hello world/Newline omission
- Hello world/Standard error
- Hello world/Text
- Hello world/Web server
- Here document
- Heronian triangles
- Hickerson series of almost integers
- Higher-order functions
- Hilbert curve
- History variables
- Hofstadter Figure-Figure sequences
- Hofstadter Q sequence
- Hofstadter-Conway $10,000 sequence
- Holidays related to Easter
- Honeycombs
- Horizontal sundial calculations
- Horner's rule for polynomial evaluation
- Host introspection
- Hostname
- Hough transform
- Huffman coding
- Hunt The Wumpus
- I before E except after C
- I.Q. Puzzle
- IBAN
- Identity matrix
- Idiomatically determine all the characters that can be used for symbols
- Idiomatically determine all the lowercase and uppercase letters
- Image convolution
- Image noise
- Imaginary base numbers
- Implicit type conversion
- Include a file
- Increment a numerical string
- Index finite lists of positive integers
- Infinity
- Inheritance/Multiple
- Inheritance/Single
- Input loop
- Input/Output for Lines of Text
- Input/Output for Pairs of Numbers
- Integer comparison
- Integer overflow
- Integer roots
- Integer sequence
- Interactive programming
- Intersecting Number Wheels
- Introspection
- Inverted index
- Inverted syntax
- Iterated digits squaring
- JSON
- Jaro distance
- Jensen's Device
- Jewels and Stones
- JortSort
- Josephus problem
- Joystick position
- Julia set
- Jump anywhere
- Just in time processing on a character stream
- K-d tree
- K-means++ clustering
- Kahan summation
- Kaprekar numbers
- Kernighans large earthquake problem
- Keyboard input/Flush the keyboard buffer
- Keyboard input/Keypress check
- Keyboard input/Obtain a Y or N response
- Keyboard macros
- Knapsack problem/0-1
- Knapsack problem/Continuous
- Knapsack problem/Unbounded
- Knight's tour
- Knuth shuffle
- Knuth's algorithm S
- Koch curve
- Kolakoski sequence
- Kosaraju
- Kronecker product
- Kronecker product based fractals
- LU decomposition
- LZW compression
- Langton's ant
- Largest int from concatenated ints
- Largest number divisible by its digits
- Last Friday of each month
- Last letter-first letter
- Law of cosines - triples
- Leap year
- Least common multiple
- Left factorials
- Leonardo numbers
- Letter frequency
- Levenshtein distance
- Linear congruential generator
- Linux CPU utilization
- List comprehensions
- List rooted trees
- Literals/Floating point
- Literals/Integer
- Literals/String
- Logical operations
- Long multiplication
- Long primes
- Longest Common Substring
- Longest common prefix
- Longest common subsequence
- Longest increasing subsequence
- Longest string challenge
- Look-and-say sequence
- Loop over multiple arrays simultaneously
- Loops/Break
- Loops/Continue
- Loops/Do-while
- Loops/Downward for
- Loops/For
- Loops/For with a specified step
- Loops/Foreach
- Loops/Increment loop index within loop body
- Loops/Infinite
- Loops/N plus one half
- Loops/Nested
- Loops/While
- Loops/Wrong ranges
- Loops/with multiple ranges
- Lucas-Lehmer test
- Lucky and even lucky numbers
- Ludic numbers
- Luhn test of credit card numbers
- MAC Vendor Lookup
- MD4
- MD5
- MD5/Implementation
- Machine code
- Mad Libs
- Magic 8-Ball
- Magic squares of doubly even order
- Magic squares of odd order
- Magic squares of singly even order
- Main step of GOST 28147-89
- Make a backup file
- Make directory path
- Man or boy test
- Mandelbrot set
- Map range
- Markov chain text generator
- Mastermind
- Matrix multiplication
- Matrix transposition
- Matrix-exponentiation operator
- Maximum triangle path sum
- Mayan numerals
- Maze generation
- Maze solving
- McNuggets Problem
- Median filter
- Memory allocation
- Memory layout of a data structure
- Menu
- Mersenne primes
- Metaprogramming
- Metered concurrency
- Mian-Chowla sequence
- Middle three digits
- Miller–Rabin primality test
- Mind boggling card trick
- Minesweeper game
- Modular arithmetic
- Modular exponentiation
- Modular inverse
- Modulinos
- Monte Carlo methods
- Montgomery reduction
- Monty Hall problem
- Morse code
- Most frequent k chars distance
- Move-to-front algorithm
- Multi-dimensional array
- Multifactorial
- Multiline shebang
- Multiple distinct objects
- Multiple regression
- Multiplication tables
- Multiplicative order
- Multisplit
- Munchausen numbers
- Munching squares
- Musical scale
- Mutual recursion
- N-body problem
- N-queens problem
- NYSIIS
- Named parameters
- Names to numbers
- Naming conventions
- Narcissist
- Narcissistic decimal number
- Native shebang
- Natural sorting
- Nautical bell
- Negative base numbers
- Nested function
- Nested templated data
- Nim Game
- Non-continuous subsequences
- Non-decimal radices/Convert
- Non-decimal radices/Input
- Non-decimal radices/Output
- Nonoblock
- Nonogram solver
- Nth root
- Null object
- Number reversal game
- Numeric error propagation
- Numerical and alphabetical suffixes
- Numerical integration
- Numerical integration/Adaptive Simpson's method
- Numerical integration/Gauss-Legendre Quadrature
- OLE Automation
- Object serialization
- Odd word problem
- Old Russian measure of length
- Old lady swallowed a fly
- One of n lines in a file
- One-dimensional cellular automata
- OpenGL
- OpenWebNet Password
- Operator precedence
- Optional parameters
- Orbital elements
- Order disjoint list items
- Order two numerical lists
- Ordered Partitions
- Ordered words
- P-value correction
- Palindrome detection
- Pangram checker
- Paraffins
- Parallel Brute Force
- Parallel calculations
- Parametrized SQL statement
- Parse an IP Address
- Parse command-line arguments
- Parsing/RPN calculator algorithm
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Partial function application
- Particle Swarm Optimization
- Partition an integer X into N primes
- Pascal matrix generation
- Pascal's triangle
- Pascal's triangle/Puzzle
- Password generator
- Pathological floating point problems
- Peaceful chess queen armies
- Pell's equation
- Pentagram
- Percentage difference between images
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Perfect numbers
- Perfect shuffle
- Perfect totient numbers
- Perlin noise
- Permutation test
- Permutations
- Permutations by swapping
- Permutations with repetitions
- Permutations/Derangements
- Permutations/Rank of a permutation
- Pernicious numbers
- Phrase reversals
- Pi
- Pick random element
- Pierpont primes
- Pig the dice game
- Pig the dice game/Player
- Pinstripe/Display
- Plasma effect
- Play recorded sounds
- Playfair cipher
- Playing cards
- Plot coordinate pairs
- Pointers and references
- Poker hand analyser
- Polymorphic copy
- Polymorphism
- Polynomial long division
- Polynomial regression
- Polyspiral
- Population count
- Power set
- Pragmatic directives
- Price fraction
- Primality by trial division
- Prime conspiracy
- Prime decomposition
- Primes - allocate descendants to their ancestors
- Primorial numbers
- Priority queue
- Probabilistic choice
- Problem of Apollonius
- Program name
- Program termination
- Proper divisors
- Pythagoras tree
- Pythagorean quadruples
- Pythagorean triples
- QR decomposition
- Quaternion type
- Queue/Definition
- Queue/Usage
- Quickselect algorithm
- Quine
- RCRPG
- RIPEMD-160
- RPG Attributes Generator
- RSA code
- Ramer-Douglas-Peucker line simplification
- Ramsey's theorem
- Random Latin Squares
- Random number generator (device)
- Random number generator (included)
- Random numbers
- Range consolidation
- Range expansion
- Range extraction
- Ranking methods
- Rate counter
- Ray-casting algorithm
- Read a configuration file
- Read a file character by character/UTF8
- Read a file line by line
- Read a specific line from a file
- Read entire file
- Real constants and functions
- Recaman's sequence
- Record sound
- Reduced row echelon form
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Regular expressions
- Remove duplicate elements
- Remove lines from a file
- Rename a file
- Rep-string
- Repeat
- Repeat a string
- Resistance Calculator
- Resistance Network Calculator
- Resistor mesh
- Respond to an unknown method call
- Return multiple values
- Reverse a string
- Reverse the gender of a string
- Reverse words in a string
- Rock-paper-scissors
- Roman numerals/Decode
- Roman numerals/Encode
- Roots of a function
- Roots of a quadratic function
- Roots of unity
- Rosetta Code/Count examples
- Rosetta Code/Fix code tags
- Rot-13
- Run-length encoding
- Runge-Kutta method
- Runtime evaluation
- Runtime evaluation/In an environment
- S-Expressions
- SEDOLs
- SHA-1
- SHA-256
- SOAP
- SQL-based authentication
- Safe primes and unsafe primes
- Sailors, coconuts and a monkey problem
- Same Fringe
- Sattolo cycle
- Scope modifiers
- Scope/Function names and labels
- Search a list
- Search a list of records
- Secure temporary file
- Self-describing numbers
- Self-hosting compiler
- Self-referential sequence
- Semiprime
- Semordnilap
- Send an unknown method call
- Send email
- Separate the house number from the street name
- Sequence of primes by trial division
- Sequence of primorial primes
- Sequence: nth number with exactly n divisors
- Sequence: smallest number greater than previous term with exactly n divisors
- Sequence: smallest number with exactly n divisors
- Set
- Set consolidation
- Set of real numbers
- Set puzzle
- Seven-sided dice from five-sided dice
- Sexy primes
- Shell one-liner
- Shoelace formula for polygonal area
- Short-circuit evaluation
- Shortest common supersequence
- Show Ascii table
- Show the epoch
- Sierpinski carpet
- Sierpinski pentagon
- Sierpinski triangle
- Sierpinski triangle/Graphical
- Sieve of Eratosthenes
- Simple database
- Simple windowed application
- Simulate input/Keyboard
- Simulate input/Mouse
- Singleton
- Singly-linked list/Element definition
- Singly-linked list/Element insertion
- Singly-linked list/Traversal
- Sleep
- Smarandache prime-digital sequence
- Smith numbers
- Snake And Ladder
- Sockets
- Sokoban
- Solve a Hidato puzzle
- Solve a Holy Knight's tour
- Solve a Hopido puzzle
- Solve a Numbrix puzzle
- Solve the no connection puzzle
- Sort a list of object identifiers
- Sort an array of composite structures
- Sort an integer array
- Sort disjoint sublist
- Sort numbers lexicographically
- Sort stability
- Sort three variables
- Sort using a custom comparator
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Bead sort
- Sorting algorithms/Bogosort
- Sorting algorithms/Bubble sort
- Sorting algorithms/Cocktail sort
- Sorting algorithms/Comb sort
- Sorting algorithms/Counting sort
- Sorting algorithms/Cycle sort
- Sorting algorithms/Gnome sort
- Sorting algorithms/Heapsort
- Sorting algorithms/Insertion sort
- Sorting algorithms/Merge sort
- Sorting algorithms/Pancake sort
- Sorting algorithms/Patience sort
- Sorting algorithms/Permutation sort
- Sorting algorithms/Quicksort
- Sorting algorithms/Radix sort
- Sorting algorithms/Selection sort
- Sorting algorithms/Shell sort
- Sorting algorithms/Sleep sort
- Sorting algorithms/Stooge sort
- Sorting algorithms/Strand sort
- Soundex
- Sparkline in unicode
- Special characters
- Special variables
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Spiral matrix
- Split a character string based on change of character
- Square but not cube
- Square-free integers
- Stable marriage problem
- Stack
- Stack traces
- Stair-climbing puzzle
- State name puzzle
- Statistics/Basic
- Statistics/Normal distribution
- Stem-and-leaf plot
- Stern-Brocot sequence
- Straddling checkerboard
- String append
- String case
- String comparison
- String concatenation
- String interpolation (included)
- String length
- String matching
- String prepend
- Strip a set of characters from a string
- Strip block comments
- Strip comments from a string
- Strip control codes and extended characters from a string
- Strip whitespace from a string/Top and tail
- Strong and weak primes
- Subleq
- Subset sum problem
- Substitution Cipher
- Substring
- Substring/Top and tail
- Subtractive generator
- Successive prime differences
- Sudoku
- Suffix tree
- Suffixation of decimal numbers
- Sum and Product Puzzle
- Sum and product of an array
- Sum digits of an integer
- Sum multiples of 3 and 5
- Sum of a series
- Sum of squares
- Sum to 100
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping
- Symmetric difference
- Synchronous concurrency
- System time
- Table creation
- Take notes on the command line
- Taxicab numbers
- Teacup rim text
- Temperature conversion
- Terminal control/Clear the screen
- Terminal control/Coloured text
- Terminal control/Cursor movement
- Terminal control/Cursor positioning
- Terminal control/Dimensions
- Terminal control/Display an extended character
- Terminal control/Hiding the cursor
- Terminal control/Inverse video
- Terminal control/Positional read
- Terminal control/Preserve screen
- Terminal control/Ringing the terminal bell
- Terminal control/Unicode output
- Ternary logic
- Test a function
- Test integerness
- Text between
- Text processing/1
- Text processing/2
- Text processing/Max licenses in use
- Textonyms
- The ISAAC Cipher
- The Name Game
- The Twelve Days of Christmas
- Thiele's interpolation formula
- Thue-Morse
- Tic-tac-toe
- Time a function
- Tokenize a string
- Tokenize a string with escaping
- Tonelli-Shanks algorithm
- Top rank per group
- Topic variable
- Topological sort
- Topological sort/Extracted top item
- Topswops
- Total circles area
- Totient function
- Trabb Pardo–Knuth algorithm
- Tree datastructures
- Tree traversal
- Trigonometric functions
- Truncate a file
- Truth table
- Twelve statements
- Two Sum
- URL decoding
- URL encoding
- URL parser
- UTF-8 encode and decode
- Ulam spiral (for primes)
- Unbias a random generator
- Undefined values
- Unicode strings
- Unicode variable names
- Universal Turing machine
- Unix/ls
- Update a configuration file
- Use another language to call a function
- Using the Meetup.com API
- Validate International Securities Identification Number
- Vampire number
- Van Eck sequence
- Van der Corput sequence
- Variable size/Get
- Variable size/Set
- Variable-length quantity
- Variables
- Variadic function
- Vector
- Vector products
- Verify distribution uniformity/Chi-squared test
- Verify distribution uniformity/Naive
- Vibrating rectangles
- Video display modes
- Vigenère cipher
- Vigenère cipher/Cryptanalysis
- Visualize a tree
- Vogel's approximation method
- Walk a directory/Non-recursively
- Walk a directory/Recursively
- Water collected between towers
- Web scraping
- Welch's t-test
- Window creation
- Window creation/X11
- Window management
- Wireworld
- Word break problem
- Word frequency
- Word search
- Word wrap
- World Cup group stage
- Write entire file
- Write float arrays to a text file
- Write to Windows event log
- XML Validation
- XML/DOM serialization
- XML/Input
- XML/Output
- XML/XPath
- Xiaolin Wu's line algorithm
- Y combinator
- Yahoo! search interface
- Yin and yang
- Zebra puzzle
- Zeckendorf arithmetic
- Zeckendorf number representation
- Zero to the zero power
- Zhang-Suen thinning algorithm
- Zig-zag matrix
- Zumkeller numbers