Advanced Python Learning Notes

Take a function as a parameter

Import mathdef Add (x, Y, f):   return f (x) + f (Y) print Add (9, math.sqrt)

Map (f, list) functions

Receives an F and a list and, by acting on each element of the list in turn, the function f, gets a new list and returns.

def f (x):   return x *= [1234]print map (f, list)  # [1  49]

Reduce (f, list) function

def f (x, y):   return x * yreduce (f, [12341*2* 3*4

Filter (f, list) function

Filters for elements that do not meet the criteria, and returns a new list of eligible elements

Sorted (list) Sort functions sorted (list, f) custom sort

Import Module

Import Math  from math import pow, sin, log

Dynamic Import Module

Try :    import jsonexcept importerror:    as JSON

Using __future__

New versions of Python introduce new features, but in fact these features already exist in the previous version. To "try out" a new feature, you can do so by importing some of the features of the __future__ module.

 from __future__ import unicode_literals

Python Module management tools
Easy_install
Pip

Create Class

class Person (object):    = person ()

To add an attribute to an instance of a class

' Wangxi '   -

Initializing instance Properties

classPerson (Object): Def __init__ (self, name, age, gender): Self.name=name Self.age=Age Self.gender=Genderuser= Person ('Wangxi', -,'male') # User.Name'Wangxi'# User.age -# User.gender'male'

Access restrictions for object properties (private property)

classCar (Object): Def __init__ (self, name, color, price): Self.name=name Self.color=Color Self.__price=Pricetesla= Car ('Tesla',' White','$23000') Tesla.name #'Tesla'Tesla.color #' White'tesla.price# Traceback (most recent): # File"<stdin>", line1,inch<module># Attributeerror:'Car' Objecthas no attribute' Price'

Creating Class properties and methods
Binding on a class, each instance owning, independent of each other

classHuman (Object): Address='Earth'__name='Mans'# Private attribute, inaccessible to Def __init__ (self, name) in an instance of class: Self.name=name def getName (self): # method of the class the first argument must be selfreturnSelf.__name # Class of methods can access private properties me= Human ('Wangxi') Me.address #'Earth'me.getname () # Self does not need an explicit pass-through

Class properties can be added and modified dynamically (all instance access class properties will change)

'  China '  'China'

If instance properties and Class properties conflict, the lookup instance property is preferred

' Hangzhou '  'Earth'

Inherited

class Person (object):  def __init__ (self, Name, gender):    = name    = gender class Student:  def __init__ (self, name, gender, score):    super (Student, self). __INIT__ (name, gender):     = Score

Polymorphic

Special methods
__str__
Turn an instance of a class into Str

The back of the feeling for me a little more than the outline, temporarily do not write down. Come back to school when you're free

Advanced Python Learning Notes