#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Mon Apr 20 21:08:08 2020
@author: root
"""
import collections
Card = collections.namedtuple('Card', ['rank','suit'])
class FrenchDeck:
ranks = [str(n) for n in range(2,11)]+list('JQKA')
suits='spades diamods clubs hearts'.split()
def __init__(self):
self._cards= [Card ('rank','suit') for suit in self.suits
for rank in self.ranks]
def __len__(self):
return len(self._cards)
def __getitem__(self,position):
return self._cards[position]
beer_card = Card('7','diamods')
print ('beer_card',beer_card)
deck=FrenchDeck()
print (len(deck))
# example1
from random import choice
choice(deck)
print (choice(deck))
#__getitem__
for card in deck:
print(card)
for card in reversed(deck):
print (card)
Card('Q','hearts') in deck
suit_values=dict(spades=3,hearts=2,diamonds=1,clubs=0)
def spades_high(card):
rank_value = FrenchDeck.ranks.index(card.rank)
return rank_value*len(suit_values)+suit_values[card.suit]
for card in sorted(deck,key=spades_high):
print (card)
"""
Python的魔法方法__getitem__ 可以让对象实现迭代功能，
这样就可以使用for...in... 来迭代该对象了
在用 for..in.. 迭代对象时，如果对象没有实现
__iter__ __next__ 迭代器协议，
Python的解释器就会去寻找__getitem__ 来迭代对象
，如果连__getitem__ 都没有定义，这解释器就会报对象不是迭代器的错误：
"""
class Animals:
def __init__(self,animal_list):
self.animals_name=animal_list
def __getitem__(self,index):
return self.animals_name[index]
animals=Animals(['dog','cat','fish'])
for animal in animals:
print (animals)
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Mon Apr 20 22:39:15 2020
@author: root
"""
from math import hypot
class Vector:
def __init__(self,x=0,y=0):
self.x=x
self.y=y
def __repr__(self):
return 'repr vector(%r,%r)'%(self.x,self.y)
def __abs__(self):
return hypot(self.x,self.y)
def __bool__(self):
return bool(abs(self))
def __add__(self,other):
x=self.x + other.x
y=self.y + other.y
return Vector(x,y)
def __mul__(self,scalar):
return Vector(self.x*scalar,self.y*scalar)
a=Vector(1,2)
b=Vector(3,4)
print (a+b)
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