零基础python教程：字典

1、a = {1:'PYTHON'}

 

b = {'key':'PYTHON'}

 

c = {"key":1}

 

上面这上三种写法都是合法的。

1、c = {"key":1,"key2":1,"key3":2}

 

for k in c:

 

   print k, c[k];

2、c = {"key":1,"key2":1,"key3":2}

 

for item in c.items():

 

   print item;

3、c = {"key":1,"key2":1,"key3":2}

 

for k, v in a.items():

 

   print k,v;

1、新增一个元素

c = {"key":1,"key2":1,"key3":2}

 

c["add"] = 100;

 

for k, v in c.items():

 

   print k,v;

2、删除元素

c = {"key":1,"key2":1,"key3":2}

 

del c["key"]

 

for k, v in c.items():

 

   print k,v;

1、c = {"key":1,"key2":1,"key3":2}

 

c["key"] = "I modify it!"

 

for k, v in c.items():

 

   print k,v;