A .python description:
1.python founder of Guido van Rossum (Guido van Rossum). Guido (turtle t) during the 1989 Christmas began to write Python language compiler, as a succession of ABC language. The name comes from Python turtle t-beloved TV series Monty Python's Flying Circus, creating between C and shell.
2.TIOBE Ranking: python # 4
3.python Application: reptiles, data analysis, component integration, network services, image processing, and numerical scientific computing
· Cloud computing: the hottest language, typical applications OpenStack
· WEB development: web development frameworks are python, for example Youtubo, Dropbox, watercress. A typical web framework Django
· Scientific computing, artificial intelligence: Typical library Numpy, SciPy, Matplotlib, Enthought, librarys, pandas
• System operation and maintenance: operation and maintenance personnel must-language
· Finance: quantitative trading, financial analysis
· Graphics GUI: PyQT, WxPython, TkInTer
4.python (interpreted language) language attribute:
· Programming language is divided into: compiled and interpreted static and dynamic languages strongly typed and weakly typed language Definition Language
· Compiled language - the compiler: compile source code into machine language, and save a binary file, the computer running the program directly in machine language, very fast. Advantages: The compiler usually have pre-compiled code optimization process. Because the compiler only once, do not need to compile and run time, so high a compiled language program execution efficiency, can operate independently from the locale. Cons: After compiling To modify need to recompile the entire module, the compiler generating machine code according to the corresponding execution environment, migration issues will arise between different operating systems, different executable files to be compiled according to the environment to run the operating system. For example: C C ++ GO ++ SWIFT OBJECT-C PASCAL
· Interpreted language - interpreter: only in the implementation of the program, one by one interpretation into computer language to the computer to perform, the development of high efficiency, but running slow. Pros: good platform compatibility, can run in any environment, very flexible, you can modify the code directly, no downtime for maintenance. Disadvantages: need to explain once every time it runs, as compiled language performance. For example: JAVASCRIPT PYTHON RUBY PHP PERL ERLANG
· Mixed language: JAVA C #
· Python advantages: ① positioning: elegant, clear and simple. Approachable. ② development of high efficiency, a strong third-party libraries. ③ high-level language. ④ portability. python interpreter running on, can run on all systems. ⑤ scalability. Be part of the program in C or C ++, and then use python. ⑥ embeddability. Python can be embedded in C or C ++ program that provides scripting capabilities to the program user. Can be written in C or C ++, Python, python also can be written in C or C ++
· Python shortcomings: ① slow. Interpreted language. ② code can not be encrypted. Source code is in the form of name text. ③ thread can not take advantage of multi-CPU problem. That global interpreter lock GIL (Global Interpreter Lock) is a tool for computer programming language interpreter for thread synchronization so that any time only one thread in execution, python thread is native operating system threads. On Linux is pthread, in windows
On to Win thread, executed entirely by the operating system thread scheduling. There are a main thread execution threads, and a plurality of user programs within a python interpreter process. Even on multi-core CPU platform, because of the GIL, the prohibition of parallel execution of multiple threads.
5.python interpreter Category:
→ python interpreter program (as interpreted computer language 01) → → computer operating system performs hardware (the CPU> Memory> Peripherals)
python .py file extension needs to run the code executed by an interpreter .py file
①CPython: C language development. Run the widest start running python interpreter CPython under Widows command line.
②IPython: Based on the interactive interpreter CPython, IPython only been enhanced in the interactive mode, and the other as CPython. Financial analysis is used to quantify. >>> CPython used as prompt and [ID] In IPython as a prompt.
③PyPy: target speed is performed using JIT technology, dynamically compiled code python (not explained), can significantly improve the execution speed of the code python. PyPy and CPython different.
④Jython: Run python java interpreter on the platform, Python code can be compiled into Java bytecode execution.
⑤IronPython Python interpreter running on the .Net platform, can be directly .Net Python code into bytecode execution.
6.2018. 10.01 released in the Python2.6 2018.12.03 Python3.0 released two versions are not compatible.