Python First lesson ———— software Installation and "Hello,world" program writing

   python software download URL:https://www.python.org/  , enter the page and click Downloads, When you point to Windows, you'll get 3.3 and 2.7 two versions, which is said to be a good 2.7 version, because 3.3 of some programs are incompatible, so I downloaded version 2.7.

    installation is simple, after downloading the direct double-click will enter the installation interface, I default installed in the C drive, has been down next will finish.

    How to run: My system is win10, so I opened the   command prompt (Administrator identity), Win7 as if no administrator, entered after entering Python, will appear "' Python ' is not an internal or external command, or a program or batch file that can be run. "This is because Windows
will look for the Python exe based on the environment variables of path, and if not found, it will be an error, so we need to modify the path environment variables in advance." Turn off the command, open the properties of this computer-advanced-environment variables-System variables--path--edit, and then add a semicolon after the value of the variable, plus C:\python27 Click OK to set it to complete,

And then open the command prompt again, enter Python, Some python information is displayed to indicate that the setting was successful. Then you can complete the simple calculation and output, for example: input 100*6 will draw 600, input print ' Hello,world ' will output hello,world.

Also recommend an editor notepad++, you can never use Word or the computer's own Notepad to write, or will give the appearance of inexplicable errors.

Python first lesson ———— software Installation and "Hello,world" program writing