Basics of Python learning notes-Python peripherals

1. System commands

1. Ctrl+D to exit Python IDLE

Enter the EOF character in the input method and type Ctrl+D

2. Command line options:

-d Provide debug output

-O Generate optimized bytecode (.pyo file)

-S Do not import the site module to find the python path at startup

　-v　Redundant output (detailed tracing of import statements)

　-m modelName Run a module as a script

　-Q opt Division option

　-c cmd runs a python script submitted as a command line string

File runs a python script from a given file

2. Expand websites and tools

1. https://pypi.python.org/pypi --Storage Python official website centralized warehouse

The program package can be downloaded from here

2. setuptools --developed based on distutils

Used to publish code and interact with pypi. You can download, build, install, upgrade, and uninstall python packages.

3. pycharm --IDE

3. Basic knowledge of python

1. #! /usr/bin/env python -- used in Unix systems, a command env, located in /usr/bin, to help the system search path to know the python parser

　2. Programming and newline writing use newline characters\ , use ''' or """

when writing string wrappers. 3. Python long integers are only limited by the total virtual memory of the user's computer.

4. Define functions, if the return value is not defined , the default value is None, the function name has the __ logo and the default is a private method

5. Commonly used built-in functions:

(1) dir([obj]) Display the properties and properties of the object A collection of methods. If the object has no parameters, the name of the global variable

is displayed. (2) help([obj]) Displays the document object string of the object in a neat and beautiful form (tree-level display) , if no parameters are provided, interactive help will be entered

　　　　(3) int(obj)　Convert an object to an integer

　　　　(4) len(obj)　　Return the length of the object

　　　　(5) open(fn,mode) Open a file named fn in mode mode

　　　 Mode: 'r' --read 'w'--write, '+'- -Read and write

　　　　(6) range([start,] stop[,step])　Returns a list of integers. The starting value is start, the default value is 0, the end value is stop-1, and step is the step size. The default value is 1

　　　　(7) input(str) Wait for the user to enter a string and provide str prompt information

　　　　　　　str(obj) Convert an object to a string

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　((obj] [] Type(obj) 　　 The type of the returned object (the return value itself is a type object) 　　

　 6. Commonly used modules

　　 　　 (1) sys 　　 Handling of the Python runtime environment Different parts

(2) The function related to OS processing operating systems

(3) Relying string, regular expression

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