python中的dict

字典的添加、删除、修改操作

dict = {"a" : "apple", "b" : "banana", "g" : "grape", "o" : "orange"}
dict["w"] = "watermelon"                              #添加
del(dict["a"])                                                 #删除
dict["g"] = "grapefruit"
print dict.pop("b")    
print dictdict.clear()                                      #清空
print dict                                                                

字典的遍历

        dict = {"a" : "apple", "b" : "banana", "g" : "grape", "o" : "orange"}
         for k in dict:    
                  print "dict[%s] =" % k,dict[k]

字典items()的使用

dict = {"a" : "apple", "b" : "banana", "c" : "grape", "d" : "orange"}

每个元素是一个key和value组成的元组，以列表的方式输出print dict.items()

调用items()实现字典的遍历

          dict = {"a" : "apple", "b" : "banana", "g" : "grape", "o" : "orange"}
          for (k, v) in dict.items():    
                  print "dict[%s] =" % k, v

调用iteritems()实现字典的遍历

        dict = {"a" : "apple", "b" : "banana", "c" : "grape", "d" : "orange"}
          print dict.iteritems()
          for k, v in dict.iteritems():    
                  print "dict[%s] =" % k, v
          for (k, v) in zip(dict.iterkeys(), dict.itervalues()):    
                  print "dict[%s] =" % k, v

每个元素是一个key和value组成的元组，以列表的方式输出
print dict.items()
dict = {"a" : "apple", "b" : "banana", "c" : "grape", "d" : "orange"}
it = dict.iteritems()
print it

遍历字典里面的内容

  dict = {'name':'python','english':33,'math':35}
  print dict.items()
  for i, j in dict.items():
   print 'dict[%s]=' % i, j
  #结果
  [('name', 'python'), ('math', 35), ('english', 33)]
  dict[name]= python
  dict[math]= 35
  dict[english]= 33

或者：

  dict = {'name':'python','english':33,'math':35}
  for i in dict:
   print 'dict[%s]=' % dict[i]
  结果：
  dict[name]= python
  dict[math]= 35
  dict[english]= 33

-------------------------------------------
success_rate = {1:'1000000',2:'200000',3:'30000'}
for k in success_rate:
    print success_rate[k]
    print k
结果：
1000000  
1
200000
2
30000
3

或者：

   for k,v in dict.iteritems():
   print 'dict[%s]' % k, v
    结果：
    dict[name] python
    dict[math] 35
    dict[english] 33