有没有一种有效的方法可以根据公共(public)值合并 python 中的两个元组列表。目前,我正在执行以下操作:
name = [
(9, "John", "Smith"),
(11, "Bob", "Dobbs"),
(14, "Joe", "Bloggs")
]
occupation = [
(9, "Builder"),
(11, "Baker"),
(14, "Candlestick Maker")
]
name_and_job = []
for n in name:
for o in occupation:
if n[0] == o[0]:
name_and_job.append( (n[0], n[1], n[2], o[1]) )
print(name_and_job)
返回:
[(9, 'John', 'Smith', 'Builder'), (11, 'Bob', 'Dobbs', 'Baker'), (14, 'Joe', 'Bloggs', 'Candlestick Maker')]
虽然此代码对于小型列表工作得很好,但对于包含数百万条记录的较长列表,它的速度令人难以置信慢。有没有更有效的写法?
编辑第一列中的数字是唯一的。
编辑 稍微修改了@John Kugelman 的代码。添加了一个 get(),以防 names 字典在 occupation 字典中没有匹配的键:
>>>> names_and_jobs = {id: names[id] + (jobs.get(id),) for id in names}
>>>> print(names_and_jobs)
{9: ('John', 'Smith', None), 11: ('Bob', 'Dobbs', 'Baker'), 14: ('Joe', 'Bloggs', 'Candlestick Maker')}
最佳答案
使用字典而不是平面列表。
names = {
9: ("John", "Smith"),
11: ("Bob", "Dobbs"),
14: ("Joe", "Bloggs")
}
jobs = {
9: "Builder",
11: "Baker",
14: "Candlestick Maker"
}
如果你需要将它们转换成这种格式,你可以这样做:
>>> {id: (first, last) for id, first, last in name}
{9: ('John', 'Smith'), 11: ('Bob', 'Dobbs'), 14: ('Joe', 'Bloggs')}
>>> {id: job for id, job in occupation}
{9: 'Builder', 11: 'Baker', 14: 'Candlestick Maker'}
然后将两者合并是小菜一碟。
names_and_jobs = {id: names[id] + (jobs[id],) for id in names}
关于python - 按值加入列表,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30631967/