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hi there
I am a bit confused regarding Phython as programming software which is been used in linux operating system. I have heard that it's too slow and various such problems. I am personally running a linux based operating system. can some on explain me about the new released version of Phython programming software.
Please provide some views regarding this
Also if it's possible try to provide a site name from where i can get it
Python is a general-purpose high-level programming language. Its design philosophy emphasizes programmer productivity and code readability. Python's core syntax and semantics are minimalistic, while the standard library is large and comprehensive. Its use of whitespace as block delimiters is unusual among popular programming languages.
Python supports multiple programming paradigms (primarily object oriented, imperative, and functional) and features a fully dynamic type system and automatic memory management, similar to Perl, Ruby, Scheme, and Tcl. Like other dynamic languages, Python is often used as a scripting language.
The language has an open, community-based development model managed by the non-profit Python Software Foundation, which maintains the de facto standard definition of the language in CPython, the reference implementation.
Python is a multi-paradigm programming language. This means that, rather than forcing programmers to adopt a particular style of programming, it permits several styles: object oriented and structured programming are fully supported, and there are a number of language features which support functional programming and aspect-oriented programming[clarification needed]. Many other paradigms are supported using extensions, such as pyDBC and Contracts for Python which allow Design by Contract. Python uses dynamic typing and a combination of reference counting and a cycle detecting garbage collector for memory management. An important feature of Python is dynamic name resolution (late binding), which binds method and variable names during program execution.
Another target of the language's design is ease of extensibility, rather than having everything built into the language core. New built-in modules are easily written in C or C++. Python can also be used as an extension language for existing modules and applications that need a programmable interface. This design, of a small core language with a large standard library and an easily-extensible interpreter, was intended by Van Rossum from the very start, due to his frustrations with ABC, which espoused the opposite mindset.
The design of Python offers limited support for functional programming in the Lisp tradition. However, there are significant parallels between the philosophy of Python and that of minimalist Lisp-family languages such as Scheme. The library has two modules (itertools and functools) that implement proven functional tools borrowed from Haskell and Standard ML.
While offering choice in coding methodology, the Python philosophy rejects exuberant syntax, such as in Perl, in favor of a sparser, less cluttered one. As with Perl, Python's developers expressly promote a particular "culture" or ideology based on what they want the language to be, favoring language forms they see as "beautiful", "explicit" and "simple". As Alex Martelli put it in his Python Cookbook (2nd ed., p.230): "To describe something as clever is NOT considered a compliment in the Python culture." Python's philosophy rejects the Perl "there is more than one way to do it" approach to language design in favor of "there should be one—and preferably only one—obvious way to do it".
Python eschews premature optimization, and moreover, rejects patches to non-critical parts of CPython which would offer a marginal increase in speed at the cost of clarity. It is sometimes described as 'slow'. However, most problems[who?] are not speed critical, and as computer hardware continues to become exponentially faster (Moore's Law), languages do have more hardware resources available. When speed is a problem, Python programmers tend to try to optimize bottlenecks by algorithm improvements or data structure changes, using a JIT compiler such as Psyco, rewriting the time-critical functions in "closer to the metal" languages such as C, or by translating Python code to C code using tools like Cython.
Python is often used as a scripting language for web applications, e.g. via mod_python for the Apache web server. With Web Server Gateway Interface a standard API has been developed to facilitate these applications. Web application frameworks or application servers like web2py, Zope, and Django support developers in the design and maintenance of complex applications.
Python has seen extensive use in the information security industry, including in exploit development. Python has been successfully embedded in a number of software products as a scripting language, including in 3D animation packages such as Maya, Softimage XSI, and Blender, and 2D imaging programs like GIMP, Inkscape, Scribus, and Paint Shop Pro. ESRI is now promoting Python as the best choice for writing scripts in ArcGIS. It has even been used in several videogames.
For many operating systems, Python is a standard component; it ships with most Linux distributions, with NetBSD, and OpenBSD, and with Mac OS X. Red Hat Linux and Fedora both use the pythonic Anaconda installer. Gentoo Linux uses Python in its package management system, Portage, and the standard tool to access it, emerge. Pardus uses it for administration and during system boot.
Statements and control flow:
Python's statements include:
- The if statement, which conditionally executes a block of code, along with else and elif (a contraction of else-if).
- The for statement, which iterates over an iterable object, capturing each element to a local variable for use by the attached block.
- The class statement, which executes a block of code and attaches its local namespace to a class, for use in object oriented programming.
- The def statement, which defines a function.
- The with statement which encloses a code block within a context manager (for example, acquiring a lock before the block of code is run, and releasing the lock afterwards).
Each statement has its own semantics: for example, the def statement does not execute its block immediately, unlike most other statements.
CPython does not support continuations, and according to Guido van Rossum it never will. However, better support for coroutine-like functionality is provided in 2.5, by extending Python's generators. Prior to 2.5, generators were lazy iterators; information was passed unidirectionally out of the generator. As of Python 2.5, it is possible to pass information back into a generator function.
Among the users of Python are YouTube and the original BitTorrent client. Large organizations that make use of Python include Google, Yahoo!, CERN, NASA,and ITA. Most of the Sugar software for the One Laptop Per Child XO, now developed at Sugar Labs, is written in Python.
Python uses duck typing and has typed objects but untyped variable names. Type constraints are not checked at compile time; rather, operations on an object may fail, signifying that the given object is not of a suitable type. Despite being dynamically typed, Python is strongly typed, forbidding nonsense operations (for example, adding a number to a string) rather than silently attempting to make sense of them.
Python allows programmers to define their own types using classes, which are most often used for an object-oriented style of programming. New instances of classes are constructed by calling the class (eg, FooClass()), and the classes themselves are instances of the metaclass type (itself an instance of itself), allowing metaprogramming and reflection.
Influences on other languages:
Python's design and philosophy have influenced several programming languages:
Pyrex and its derivative Cython are code translators that are targeted at writing fast C extensions for the CPython interpreter. The language is mostly Python with syntax extensions for C and C++ features. Both languages produce compilable C code as output.
Boo uses indentation, a similar syntax, and a similar object model. However, Boo uses static typing and is closely integrated with the .NET framework.
Cobra is similar to Python, using indentation for blocks. It offers optional static typing and generates code designed for .NET/Mono. Cobra directly supports design-by-contract.
ECMAScript borrowed iterators, generators and list comprehensions from Python.
Groovy was motivated by the desire to bring the Python design philosophy to Java.Converge is syntactically similar to Python, but has a novel approach to generators and backtracking as well as macros and compile-time metaprogramming.
OCaml has an optional syntax, called twt (That Whitespace Thing), and a new Batteries Included approach, both inspired by Python.
Python's development practices have also been emulated by other languages. The practice of requiring a document describing the rationale for, and issues surrounding, a change to the language (ie, a PEP) is also used in Tcl and Erlang because of Python's influence.
Python has a large standard library, commonly cited as one of Python's greatest strengths, providing pre-written tools suited to many tasks. This is deliberate and has been described as a "batteries included" Python philosophy. The modules of the standard library can be augmented with custom modules written in either C or Python. Recently, Boost C++ Libraries includes a library, Boost.Python, to enable interoperability between C++ and Python. Because of the wide variety of tools provided by the standard library, combined with the ability to use a lower-level language such as C and C++, which is already capable of interfacing between other libraries, Python can be a powerful glue language between languages and tools.
The standard library is particularly well tailored to writing Internet-facing applications, with a large number of standard formats and protocols (such as MIME and HTTP) already supported. Modules for creating graphical user interfaces, connecting to relational databases, arithmetic with arbitrary precision decimals, manipulating regular expressions, and doing unit testing are also included.
Some parts of the standard library are covered by specifications (for example, the WSGI implementation wsgiref follows PEP 333), but the majority of the modules are not. They are specified by their code, internal documentation, and test suite (if supplied). However, because most of the standard library is cross-platform Python code, there are only a few modules that must be altered or completely rewritten by alternative implementations.
Python 3.0, also known as “Python 3000” or “Py3K”, is the first ever intentionally backwards incompatible Python release. There are more changes than in a typical release, and more that are important for all Python users. Nevertheless, after digesting the changes, you’ll find that Python really hasn’t changed all that much – by and large, we’re mostly fixing well-known annoyances and warts, and removing a lot of old cruft.
This article doesn’t attempt to provide a complete specification of all new features, but instead tries to give a convenient overview. For full details, you should refer to the documentation for Python 3.0, and/or the many PEPs referenced in the text. If you want to understand the complete implementation and design rationale for a particular feature, PEPs usually have more details than the regular documentation; but note that PEPs usually are not kept up-to-date once a feature has been fully implemented.
Due to time constraints this document is not as complete as it should have been. As always for a new release, the Misc/NEWS file in the source distribution contains a wealth of detailed information about every small thing that was changed.
Views And Iterators Instead Of Lists
- dict methods dict.keys(), dict.items() and dict.values() return “views” instead of lists. For example, this no longer works: k = d.keys(); k.sort(). Use k = sorted(d) instead (this works in Python 2.5 too and is just as efficient).
Also, the dict.iterkeys(), dict.iteritems() and dict.itervalues() methods are no longer supported.- map() and filter() return iterators. If you really need a list, a quick fix is e.g. list(map(...)), but a better fix is often to use a list comprehension (especially when the original code uses lambda), or rewriting the code so it doesn’t need a list at all. Particularly tricky is map() invoked for the side effects of the function; the correct transformation is to use a regular for loop (since creating a list would just be wasteful).
- range() now behaves like xrange() used to behave, except it works with values of arbitrary size. The latter no longer exists.
- zip() now returns an iterator.
You can Download This Extreme Programming Software from:
DOWNLOAD For Gzipped source tar ball (3.0.1) (sig)
DOWNLOAD For Bzipped source tar ball (3.0.1) (sig)