Learn Python-Lesson 1: Basic Introduction, learn python-Lesson 1

Learn Python-Lesson 1: Basic Introduction, learn python-Lesson 1
Python past and present

The founder of python is Guido van rosum ). During the Christmas period of 1989, Guido fansoum was determined to develop a new script interpreter to pass the time in Amsterdam as an inheritance of the ABC language.

Why Python instead of other languages?C, Python, Java, and C #

C language: the code is compiled to obtain the machine code. The machine code is directly executed on the processor, and each command controls CPU work.

Other languages: the code is compiled to get the bytecode. The virtual machine executes the bytecode and converts it to the machine code, and then runs it on the processor.

Python and C Python are developed by C.

For usage: Python class libraries are complete and simple to use. To implement the same function, Python 10 lines of code can solve the problem, and C may need 100 lines or more.
For speed: Compared with C, Python runs slowly.

Python, Java, and C #

For use: the original Linux Python is not available in other languages; The above languages have very rich class library support
For speed: Python speedPossibleSlightly inferior

Therefore, there is no essential difference between Python and other languages. The other difference is that Python is good at a certain field, rich talents, and preemptible.

Python type

• Cpython
  Python official version, which is implemented in C language and most widely used. CPython converts the source file (py file) into a bytecode file (pyc file) and runs on a Python virtual machine.
• Jyhton
  For Java Implementation of Python, Jython dynamically compiles Python code into Java bytecode and runs it on JVM.
• IronPython
  IronPython compiles Python code into C # bytecode and runs it on the CLR. (Similar to Jython)
• PyPy (special)
  Python implements Python, and then encodes Python bytecode into machine code.
• RubyPython, Brython...

Python Environment Install Python Windows:

Install Python

Configure the python Environment

Linux:

Linux yum dependency comes with Python. To prevent errors, the update here is actually to install another Python

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View the default Python versionpython -V  1Install gcc for compiling Python source code    yum install gcc2Download the source code package, https://www.python.org/ftp/python/3, Decompress and enter the source code file4, Compilation and Installation    ./configure    make all    make install5View version    /usr/local/bin/python2.7 -V6Modify the default Python version    mv /usr/bin/python /usr/bin/python2.6    ln -s /usr/local/bin/python2.7 /usr/bin/python7To prevent yum execution exceptions, modify the Python version used by yum    vi /usr/bin/yum    Set the header#! /Usr/bin/python #! /Usr/bin/python2.6