python - 对Python字典列表进行排序

Question

我有这个代码:

from BeautifulSoup import BeautifulSoup

TABLE_CONTENT = [['958','<a id="958F" href="javascript:c_row(\'958\')" title="go to map"><img src="/images/c_map.png" border="0"></a>','USA','Atmospheric','<a href="javascript:c_ol(\'958\')" title="click date time to show origin_list (evid=958)">1945/07/16 11:29:45</a>','33.6753','-106.4747','','-.03','21','','','TRINITY','&nbsp;','&nbsp;','<a href="javascript:c_md(\'958\')" title="click here to show source data">SourceData</a>','&nbsp;'],['959','<a id="959F" href="javascript:c_row(\'959\')" title="go to map"><img src="/images/c_map.png" border="0"></a>','USA','Atmospheric','<a href="javascript:c_ol(\'959\')" title="click date time to show origin_list (evid=959)">1945/08/05 23:16:02</a>','34.395','132.4538','','-.58','15','','','LITTLEBOY','&nbsp;','&nbsp;','<a href="javascript:c_md(\'959\')" title="click here to show source data">SourceData</a>','&nbsp;']]

EVENT_LIST = []
for EVENT in TABLE_CONTENT:
    events = {}
    for index, item in enumerate(EVENT):
        if index == 0:
            events['id'] = item
        if index == 4:
            soup = BeautifulSoup(item)
            for a in soup.findAll('a'):
                events['date'] = ''.join(a.findAll(text=True))
        if index == 2:
            events['country'] = item
        if index == 3:
            events['type'] = item
        if index == 5:
            events['lat'] = item
        if index == 6:
            events['lon'] = item
        if index == 8:
            events['depth'] = item
        if index == 9:
            events['yield'] = item
        if index == 12:
            events['name'] = item
    sorted(events, key=lambda key: events['id'])
    EVENT_LIST.append(events)
    print '=== new record ==='
EVENT_LIST.sort(key=lambda x: x['id'])
print EVENT_LIST

我遇到的第一个问题是，在 EVENT_LIST 中，字典对象的顺序与添加到列表中的顺序不同，例如，当我打印结果时，“lat”和“lon”不是按顺序:

[{'name': 'TRINITY', 'country': 'USA', 'lon': '-106.4747', 'yield': '21', 'lat': '33.6753', 'depth': '-.03', 'date': u'1945/07/16 11:29:45', 'type': 'Atmospheric', 'id': '958'}, {'name': 'LITTLEBOY', 'country': 'USA', 'lon': '132.4538', 'yield': '15', 'lat': '34.395', 'depth': '-.58', 'date': u'1945/08/05 23:16:02', 'type': 'Atmospheric', 'id': '959'}]

还有更好的方法来编写这段代码吗？

Answer 1

您可以使用 OrderedDict 保留插入字典的顺序。容器。来自手册:

Return an instance of a dict subclass, supporting the usual dict methods. An OrderedDict is a dict that remembers the order that keys were first inserted. If a new entry overwrites an existing entry, the original insertion position is left unchanged. Deleting an entry and reinserting it will move it to the end.

此功能自 2.7 版本以来才出现。

@更好的方法:您可以将后续的 if index == ... 更改为 elif index == ... 因为，如果索引为 2，它永远不会可以是 5。或者您可以存储索引/键组合并使用它们来存储您的项目。示例(未尝试):

combos={
        0: 'id',
        2: 'country',
        3: 'type',
        5: 'lat',
        6: 'lon',
        8: 'depth',
        9: 'yield',
        12: 'name' }

...

for index, item ...:
    if index == 4:
        soup = BeautifulSoup(item)
        for a in soup.findAll('a'):
        events['date'] = ''.join(a.findAll(text=True))
    elif index in combos:
        events[combox[index]]=item

我想你明白了。