《Learn Python》学习笔记

Part 3 || Chapter 15 Python Docs

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1. Where can find Python Docs resources ?

Comment in Python file  : # this is a single line comment.

dir() :

docstring : __doc__

Python Doc : help()

Standard manual set

Web Resources / Books

2. How to get detailed information about the attributes of an object ?

__doc__ : module docstring is on the *.py head; function and class docstring place in head in

function / class body respectively.

Eg. Module.__doc__; Module.func.__doc__;Module.cls.__doc__;Module.cls.method.__doc__;

help() : Auto generate module info in specific way.

Python Module Document : all

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Part 3 : practice

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Part 4 || Chapter 16  Function Basics

0. function is  a packaged procedure invoked by its name,

functions are also basic program structure Python provide for maximizing

code reuse,which split complex complex systems into manageable parts.

declare function        -->  def / lambda

scope visibility          -->  global / nonlocal

come results              -->  return / yield

1.How to create function ?

def statements are coded in module files and run to generate functions when

the module file first imported.

def create an function object and assigns it to a name [function name]

lambda  create an object but return it as a result.

return sends a result object back to caller. A return without a value will return

None,the default value.

yield send a result object back to the caller,but remember where it left off.[generators]

2. Variable Visibility Scope

global declare module-level variables that are to be assigned,which can be used to retain

state - information remembered between functions call,without by sharing

global names.

Function's arguments ,return values and variables are not declare and no type constraints,

which mean that they can be any types.

function definition happens at Python runtime.