Python 如何防止OrderedDict插入元素而不是将其添加到末尾?
那么为什么会发生这种情况呢 我有两本字典:Python 如何防止OrderedDict插入元素而不是将其添加到末尾?,python,dictionary,ordereddictionary,Python,Dictionary,Ordereddictionary,那么为什么会发生这种情况呢 我有两本字典: d_names d_new_names 第二个是第一个的重新排序版本。这是因为我明白这一点 为此,我首先创建一个有序列表: l_new_names = [] for s_number in d_names: for s_week_number in d_names[s_number]: l_new_names.append([s_number, s_week_number]) print "l_new_names befor
d_names
d_new_names
第二个是第一个的重新排序版本。这是因为我明白这一点
为此,我首先创建一个有序列表:
l_new_names = []
for s_number in d_names:
for s_week_number in d_names[s_number]:
l_new_names.append([s_number, s_week_number])
print "l_new_names before sort = %s" % l_new_names
l_new_names.sort()
print "l_new_names after sort = %s" % l_new_names
然后我创建并填充新词典的第一级:
d_new_names = ordereddict.OrderedDict()
for s_number, _ in l_new_names:
if s_number in d_new_names:
print "NOT creating d_new_names[%s]" % s_number
else:
print "creating d_new_names[%s]" % s_number
d_new_names[s_number] = {}
d_new_names[s_number][NAME] = d_names[s_number][NAME]
for s_number, s_week_number in l_new_names:
d_new_names[s_number][s_week_number] = {}
d_new_names[s_number][s_week_number][DATE] = d_names[s_number][s_week_number][DATE]
d_new_names[s_number][s_week_number][PRICE] = d_names[s_number][s_week_number][PRICE]
d_new_names[s_number] = {}
然后我创建第二级并填充字典:
d_new_names = ordereddict.OrderedDict()
for s_number, _ in l_new_names:
if s_number in d_new_names:
print "NOT creating d_new_names[%s]" % s_number
else:
print "creating d_new_names[%s]" % s_number
d_new_names[s_number] = {}
d_new_names[s_number][NAME] = d_names[s_number][NAME]
for s_number, s_week_number in l_new_names:
d_new_names[s_number][s_week_number] = {}
d_new_names[s_number][s_week_number][DATE] = d_names[s_number][s_week_number][DATE]
d_new_names[s_number][s_week_number][PRICE] = d_names[s_number][s_week_number][PRICE]
d_new_names[s_number] = {}
当我将词典内容写入一个文件时,我惊讶地看到以下顺序:
writing week:13
writing week:15
writing week:14
writing week:16
也就是说,第15周先于第14周
经过调查(每次通过第二个循环打印OrderedDict),我发现(编号对应于循环):
有人能解释一下发生了什么以及我是如何解决的吗?您正在将周数插入常规词典,而不是有序词典:
d_new_names = ordereddict.OrderedDict()
for s_number, _ in l_new_names:
if s_number in d_new_names:
print "NOT creating d_new_names[%s]" % s_number
else:
print "creating d_new_names[%s]" % s_number
d_new_names[s_number] = {}
d_new_names[s_number][NAME] = d_names[s_number][NAME]
for s_number, s_week_number in l_new_names:
d_new_names[s_number][s_week_number] = {}
d_new_names[s_number][s_week_number][DATE] = d_names[s_number][s_week_number][DATE]
d_new_names[s_number][s_week_number][PRICE] = d_names[s_number][s_week_number][PRICE]
d_new_names[s_number] = {}
这里,d\u新的\u名称
在一个有序字典中,因此s\u编号
值按插入顺序保留,但键引用普通字典
然后,使用这些普通字典存储每周信息:
d_new_names[s_number][s_week_number] = {}
因此,您的
s\u week\u编号
周编号不会按插入顺序保存,而是按照普通字典的任意顺序进行。请发布示例数据以运行代码。这段代码不是复制问题的最小完整代码,而是其他错误的代码;有序字典非常保持原始的插入顺序。就是这样!我将您引用的两行代码改为:d_new_names[s_po_number]=ordereddict.ordereddict()
和d_new_names[s_po_number][s_week_number]=ordereddict.ordereddict()
,现在可以使用了,非常感谢。(从一个问题到另一个解决方案需要6分钟——我的一个问题是我见过的最好的一个问题!:)[我自己不会找到这个,干杯!]@Wikis如果你包括一个完整的MCVE,我肯定会成功的。:-)