import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
dic['k3'] = 'v3'
print(dic)
#输出：OrderedDict([('k1', 'v1'), ('k2', 'v2'), ('k3', 'v3')])
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
dic.clear()
print(dic)
#输出：OrderedDict()
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
new_dic = dic.copy()
print(new_dic)
#输出：OrderedDict([('k1', 'v1'), ('k2', 'v2')])
-
fromkeys(指定一个列表，把列表中的值作为字典的key,生成一个字典)
import collections
dic = collections.OrderedDict()
name = ['tom','lucy','sam']
print(dic.fromkeys(name))
print(dic.fromkeys(name,20))
#输出：OrderedDict([('tom', None), ('lucy', None), ('sam', None)])
# OrderedDict([('tom', 20), ('lucy', 20), ('sam', 20)])
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
print(dic.items())
#输出：odict_items([('k1', 'v1'), ('k2', 'v2')])
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
print(dic.keys())
# 输出：odict_keys(['k1', 'k2'])
-
move_to_end(指定一个key，把对应的key-value移到最后)
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
dic['k3'] = 'v3'
dic.move_to_end('k1')
print(dic)
# 输出：OrderedDict([('k2', 'v2'), ('k3', 'v3'), ('k1', 'v1')])
-
pop(获取指定key的value，并在字典中删除)
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
dic['k3'] = 'v3'
k = dic.pop('k2')
print(k,dic)
# 输出：v2 OrderedDict([('k1', 'v1'), ('k3', 'v3')])
-
popitem(按照后进先出原则，删除最后加入的元素，返回key-value)
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
dic['k3'] = 'v3'
print(dic.popitem(),dic)
print(dic.popitem(),dic)
# 输出：('k3', 'v3') OrderedDict([('k1', 'v1'), ('k2', 'v2')])
# ('k2', 'v2') OrderedDict([('k1', 'v1')])
-
setdefault(获取指定key的value，如果key不存在，则创建)
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
dic['k3'] = 'v3'
val = dic.setdefault('k5')
print(val,dic)
# 输出：None OrderedDict([('k1', 'v1'), ('k2', 'v2'), ('k3', 'v3'), ('k5', None)])
-
values(获取字典所有的value，返回一个列表)
import collections
dic = collections.OrderedDict()
dic['k1'] = 'v1'
dic['k2'] = 'v2'
dic['k3'] = 'v3'
print(dic.values())
# 输出：odict_values(['v1', 'v2', 'v3'])
| 
转播
