每天一個python 小案例——字典

#!/usr/bin/env python

cities = {'CA':'CHINA','MI':'MISS','FL':'FAMMLY'}

cities['NY'] = 'NEW York'

cities['OR'] = 'Portland'

print cities

def find_city(themap,state):

if state in themap:

return themap[state]

else:

return "Not found."

cities['_find'] = find_city #cities_['_find']賦值find_city

while True:

print "State?(NETER to quit)",

state = raw_input(">")

if not state:break

city_found = cities['_find'](cities,state)#city_found=cities["_find"](cities,state) 等價於city_found=find_city(cities,state)

print city_found

基本字典操作
（1）len(d)返回d中項（鍵-值對）的數量；
（2）d[k]返回關聯到k上的值；
（3）d[k]=v將值v關聯到鍵k上；
（4）del d[k]刪除鍵爲k的項；
（5）k in d檢查d中是否有含鍵爲k的項；