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Python (programming language)

general-purpose, high-level programming language

Python is an open source programming language that was made to be easy-to-read and powerful. A Dutch programmer named Guido van Rossum made Python in 1991. He named it after the television show Monty Python's Flying Circus. Many Python examples and tutorials include jokes from the show.

Python
Python logo and wordmark.svg
Designed byGuido van Rossum
DeveloperPython Software Foundation
Stable release3.7.2 / 24 December 2018; 8 months ago (2018-12-24)[1]
2.7.15 / 1 May 2018; 16 months ago (2018-05-01)[2]
Typing disciplineDuck, dynamic, gradual (since 3.5),[3] strong
PlatformAny
OSAny
LicensePython License[4]
Filename extensions.py, .pyo, .pyc
Websitehttps://www.python.org
Major implementations
CPython, IronPython, Jython, MicroPython, Numba, PyPy, Stackless Python, CircuitPython
Dialects
Cython, RPython

Python is an interpreted language. Interpreted languages do not need to be compiled to run. A program called an interpreter runs Python code on almost any kind of computer. This means that a programmer can change the code and quickly see the results. This also means Python is slower than a compiled language like C, because it is not running machine code directly.

Python is a good programming language for beginners. It is a high-level language, which means a programmer can focus on what to do instead of how to do it. Writing programs in Python takes less time than in some other languages.

Python drew inspiration from other programming languages like C, C++, Java, Perl, and Lisp.

Python's developers strive to avoid premature optimization. Additionally, they reject patches to non-critical parts of the CPython reference implementation that would provide improvements on speed. When speed is important, a Python programmer can move time-critical functions to extension modules written in languages such as C or PyPy, a just-in-time compiler. Cython is also available. It translates a Python script into C and makes direct C-level API calls into the Python interpreter.

Keeping Python fun to use is an important goal of Python’s developers. It reflects in the language's name, a tribute to the British comedy group Monty Python. In occasionally, they are playful approaches to tutorials and reference materials, such as referring to spam and eggs instead of the standard foo and bar.

Python useEdit

Python is used by hundreds of thousands of programmers and is used in many places. Sometimes only Python code is used for a program, but most of the time it is used to do simple jobs while another programming language is used to do more complicated tasks.

Its standard library is made up of many functions that come with Python when it is installed. On the Internet there are many other libraries available that make it possible for the Python language to do more things. These libraries make it a powerful language; it can do many different things.

Some things that Python is often used for are:

  • Web development
  • Scientific programming
  • Desktop GUIs
  • Network programming
  • Game programming.

SyntaxEdit

Python has a very easy-to-read syntax. Some of Python's syntax comes from C, because that is the language that Python was written in. But Python uses whitespace to delimit code: spaces or tabs are used to organize code into groups. This is different from C. In C, there is a semicolon at the end of each line and curly braces ({}) are used to group code. Using whitespace to delimit code makes Python a very easy-to-read language.

Statements and control flowEdit

Python's statements include:

  • The assignment statement, or the = sign. In Python, the statement x = 2 means that the name x is bound to the integer 2. Names can be rebound to many different types in Python, which is why Python is a dynamically typed language.
  • The if statement, which runs a block of code if certain conditions are met, along with else and elif (a contraction of else if from other programming languages). The elif statement runs a block of code if the previous conditions are not met, but the conditions for the elif statement are met. The else statement runs a block of code if none of the previous conditions are met.
  • The for statement, which iterates over an iterable object such as a list and binds each element of that object to a variable to use in that block of code, which creates a for loop.
  • The while statement, which runs a block of code as long as certain conditions are met, which creates a while loop.
  • The def statement, which defines a function or method.
  • The pass statement, which means "do nothing."
  • The class statement, which allows the user to create their own type of objects like what integers and strings are.
  • The import statement, which imports Python files for use in the user's code.
  • The print statement, which outputs various things to the console.

ExpressionsEdit

Python's expressions include some that are similar to other programming languages and others that are not.

  • Addition, subtraction, multiplication, and division, represented by +, -. *, and /.
  • Exponents, represented by **.
  • To compare two values, Python uses ==.
  • Python uses the words "and", "or", and "not" for its boolean expressions.

ExampleEdit

This is a small example of a Python program. It shows "Hello World!" on the screen.

print("Hello World!")

# This code does the same thing, only it is longer:

ready = True
if ready:
    print("Hello World!")

Python also does something called "dynamic variable assignment". This means that when a number or word is made in a program, the user does not have to say what type it is. This makes it easier to reuse variable names, making fast changes simpler. An example of this is shown below. This code will make both a number and a word, and show them both, using only one variable.

x = 1
print(x)
x = "Word"
print(x)

In a "statically typed" language like C, a programmer would have to say whether x was a number or a word before C would let the programmer set up x, and after that, C would not allow its type to change from a number to a word.

ReferencesEdit

  1. Deily, Ned (24 December 2018). "Python 3.7.2 and 3.6.8 are now available". Python Insider. The Python Core Developers. Retrieved 24 December 2018.
  2. Peterson, Benjamin (1 May 2018). "Python 2.7.15 released". Python Insider. The Python Core Developers. Retrieved 1 May 2018.
  3. "PEP 483 -- The Theory of Type Hints". Python.org.
  4. "Python legal statements". Python Software Foundation. Retrieved January 28, 2012.

Other websitesEdit