day1 computer application principle

- What is language? 
    Language is the medium of communication between people. 

- What is the programming language? 
    Programming language is communication between man and computer media. 

- Why learn programming? 
    Let the machine replace manpower, the service of humanity. 

**** : What is software (programs)? 
    A pile of documents consisting of text inside is a bunch of code. 

- the five components of the computer dictation :()
     - the CPU: + Control operation (corresponding to human brain)
     - the memory: a storage device for temporarily storing data. Powered data exists, power data loss.
    - hard drive (external memory): used to permanently store data, power is not lost.
    - Input devices: keyboard, mouse ...
     - output devices: monitors, audio ...


 - Operating System:
     - Windows: 
        Microsoft's operating system, generally used for office work, entertainment (movies, play games). 

    - Mac: 
        Apple's operating system, generally used for office, with pictures and video ...

     - Linux:
        As the operating system for the server side. 


- Programming Language Category
     - machine language: 
        refers to the machine directly you can read text, binary form of expression. 
        0101010111011101110001 
        010 : Your
         010 : U
         10101110 : handsome 

        advantages: high efficiency 
        Disadvantages: the development of efficient low

     - assembly language: 
        Alternative binary by some of the characters, in order to improve development efficiency. 
        A: 1,010,101,011 

        advantages: 
            the efficiency slightly. (Low compared to machine language) 

        Disadvantages: 
            low efficiency of development. 

    - high-level language: 
        closer to human language called high-level language. 
        It is best able to understand the human character. 

        For example: python \ java \ C ... 

        advantages: 
            high development efficiency. 

        Disadvantages:
            Efficiency, lower than the machine assembly language. 



-Compiled language: 
    similar Xinhua Dictionary, the Oxford English Dictionary. 
    Advantages: 
        high efficiency. 
    Disadvantages: 
        low efficiency of development. 

- interpreted language: 
    similar to simultaneous interpretation, while the implementation side translation. 
    Advantages: 
        high development efficiency. 
    Disadvantages: 
        low efficiency. 

Note: The computer can only recognize binary characters. 

Python: is an interpreted language. 



Python:
     1 written in python code in two ways:
         - Interactive environments: 
            temporary valid, invalid closed. 

        - python file (******* ) 
            permanently save python code, all files are python .py file. 

            Py file creation steps: -> project folder right-click -> New -> 
                python File (write the name python file)

     2 execute python code things will happen:
         1) To execute the python interpreter, load python interpreter.
        2 ) to load the python file into memory.
        3 ) perform python code. 


    3 . Variable 
        variable amount is variable, the equivalent of human memory. 
        Note: The first definition, after the call. 
        - variable name: variable values and binding relationship, the equivalent of house number variable values.
        - = : variable name and a variable value bind
         - variable values: generating in memory, the effective power, to power loss. 


    4 .python data type 

        type (variable name): used to view data types. ,