Rumah > Artikel > pembangunan bahagian belakang > python3 OrderedDict类(有序字典)使用方法
创建有序字典
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')])
clear(清空有序字典)
import collections dic = collections.OrderedDict() dic['k1'] = 'v1'dic['k2'] = 'v2'dic.clear()print(dic)#输出:OrderedDict()
copy(拷贝)
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)])
items(返回由“键值对组成元素“的列表)
import collections dic = collections.OrderedDict() dic['k1'] = 'v1'dic['k2'] = 'v2'print(dic.items())#输出:odict_items([('k1', 'v1'), ('k2', 'v2')])
keys(获取字典所有的key)
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'])
Atas ialah kandungan terperinci python3 OrderedDict类(有序字典)使用方法. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!