Python Foundation 13th day--sys module, logging module, JSON module, pickle module

one, sys module1. Definition:

A module that interacts with the Python interpreter

2, sys module commonly used methods(1) sys.argv method

Definition: Command line Arguments list, the first element is the path of the program itself

Cases:

Import Sysprint (SYS.ARGV) # SYS.ARGV just reflects the current module name, with a list of # and Pycharm software automatically adds absolute path to us

Output: # This is not the right result, because it's pycharm.

['C:/users/william/pycharmprojects/python_item2/study/day12/sys module/argv method. py']

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The result of the output shown in the terminal with this sys.argv method is the correct result:

Therefore, in the work, it must be the result of the output of the terminal to prevail

Focus:

SYS.ARGV commonly used to pass user input account number and password

Example 1:

Example 2:

In order to find the user name and password more conveniently, it is best to add "-U" and "-P" before the account password.

(2) Sys.exit () method

Definition: Exit the program, exit normally (0)

Cases:

An example that has been done before: there are 10 numbers when the loop to the number 8 o'clock exits the program

Sys.exit ()

Import Syscount = 1while count <:    print (count)    if Count = = 8:        sys.exit ()    count + = 1print (' ending ')

Output Result:

12345678

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(3) Sys.version method

Definition: Get version information for the Pyhon interpreter

(4) Sys.maxint method

Definition: the largest int value

(5) Sys.path method

Definition: Returns the search path of the module, initializing the value using the PYTHONPATH environment variable

Example 1:

Import Sysprint (Sys.path) # Get the search path for the module

Output Result:

['C:\\users\\william\\pycharmprojects\\python_item2\\study\\day12\\sys Module','c:\\users\\william\\pycharmprojects\\python_item2','C:\\python\\python36\\python36.zip','C:\\python\\python36\\dlls','C:\\python\\python36\\lib','c:\\python\\python36','c:\\users\\william\\appdata\\roaming\\python\\python36\\site-packages','c:\\python\\python36\\lib\\site-packages']

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To add an environment variable:

Example 2: Use Sys.path to add a custom module1.py module to a python environment variable.

(6) Sys.platform method

Definition: Returns the operating system platform name

Cases:

second, logging module1. Definition

Log module

2. Common methods of logging module

(1) Logging.debug () method

(2) Logging.info () method

(3) logging.warning () method

(4) Logging.error () method

(5) Logging.critical () method

third, the JSON module

Four, pickle module

Python Foundation 13th day--sys module, logging module, JSON module, pickle module