Python Pandas根据另一个列中的总数从另一个dataFrame中选择值 [英] Python Pandas Select values from another dataFrame depending on the total from another column

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问题描述

我在下面有一个DataFrame,但我需要根据已取消和订购的列从每个代码中选择行.

I have a DataFrame below but I need to select rows from each code depending on the canceled and order column.

说代码xxx的顺序为[6、1、5、1],顺序为11.我需要一种算法,该算法可以选择满足总11条说的顺序的行[6& 5]

Say code xxx has orders [6, 1, 5, 1] and the order is 11. I need an algorithm that can select the rows that meet the total 11 say rows with orders [6 & 5]

如果没有行匹配,则选择最接近的ID,并将其添加到列表中,其与取消的差异如下所示:111111是所选ID,而35是55与20之间的差异.我需要一种能够处理10k的算法行

If No rows match, then select the closest ids and add it to a list with their difference from the canceled as below 111111 is the selected id and 35 is the diff between 55 and 20. i need an algorithm that can handle 10k Rows

我的预期输出

**code**    **canceled**    **order**              **ids**
     xxx           11.0            13     [128281, 128283]
     cvd             20            55         (111111, 35)

import pandas as pd

ccc = [
    {"code":"xxx","canceled":11.0,"id":"128281","order":6},
    {"code":"xxx","canceled":11.0,"id":"128282","order":1},
    {"code":"xxx","canceled":11.0,"id":"128283","order":5},
    {"code":"xxx","canceled":11.0,"id":"128284","order":1},
    {"code":"xxS","canceled":0.0,"id":"108664","order":4},
    {"code":"xxS","canceled":0.0,"id":"110515","order":1},
    {"code":"xxS","canceled":0.0,"id":"113556","order":1},
    {"code":"eeS","canceled":5.0,"id":"115236","order":1},
    {"code":"eeS","canceled":5.0,"id":"108586","order":1},
    {"code":"eeS","canceled":5.0,"id":"114107","order":1},
    {"code":"eeS","canceled":5.0,"id":"113472","order":3},
    {"code":"eeS","canceled":5.0,"id":"114109","order":3},
    {"code":"544W","canceled":44.0,"id":"107650","order":20},
    {"code":"544W","canceled":44.0,"id":"127763","order":4},
    {"code":"544W","canceled":44.0,"id":"128014","order":20},
    {"code":"544W","canceled":44.0,"id":"132434","order":58},
    {"code":"cvd","canceled":20.0,"id":"11111","order":55},
    {"code":"eeS","canceled":5.0,"id":"11111","order":5}
]

我尝试了以下可行的解决方案,但是如果存在,我需要寻找确切的值.我还需要选择最可能的ID总计为已取消值.我想消除这种(111111, 35)

I tried a solution the below solution it works but i need to look for the exact value if it exists. I also need to select the most possible ids that sum up to the canceled value. I want to eliminate the possibility of having this (111111, 35)

df = pd.DataFrame(ccc)

def selected_ids(datum):
    ids = datum.id
    nbc = int(datum.canceled)
    order = datum.order
    count = []
    arr = []

    for loc, i in enumerate(order):

        count.append(i)
        arr.append(ids[loc])

        if nbc == int(i):
            return ids[loc]

        elif nbc  == 0:
            return ''

        elif nbc  < int(i):
            return (ids[loc], (int(i)-nbc))

        if nbc < sum(count):
             return [arr[:-1], (arr[-1],sum(count)-nbc)]

xcv = df.sort_values('order').groupby('code').agg({
    'code':'first',
    'canceled': 'first',
    'order': list,
    'id':list
})
xcv['Orders_to_cancel'] = xcv.apply(
    selected_ids, axis = 1
)
xcv

推荐答案

怎么样(出于可读性考虑,数据框仅限于代码xxxcvdeeS)

df2 = df.groupby('code').agg({
    'canceled' : 'first',
    'order'    : list,
    'id'       : list
}).reset_index().rename(
    columns={
        'id'    : 'ids',
        'order' : 'orders',
    }
)
df2['orders_sum'] = df2.orders.apply(sum)

print(df2)
###   code  canceled              orders                                              ids  orders_sum
### 0  cvd      20.0                [55]                                          [11111]          55
### 1  eeS       5.0  [1, 1, 1, 3, 3, 5]  [115236, 108586, 114107, 113472, 114109, 11111]          14
### 2  xxx      11.0        [6, 1, 5, 1]                 [128281, 128282, 128283, 128284]          13

然后我们可能首先要检查某些ids是否已经具有直接适合canceled值的order值.

We may then first want to check if some ids already have an order value that fits directly the canceled value.

df2['direct_ids'] = df2.apply(
    lambda r: [
        i for o, i in zip(r.orders, r.ids)
        if o == r.canceled
    ],
    axis = 1
)

print(df2.loc[:, ('code', 'canceled', 'direct_ids')])   
###   code  canceled direct_ids
### 0  cvd      20.0         []
### 1  eeS       5.0    [11111]    # We could have had more than one id, hence the list
### 2  xxx      11.0         []

...否则,我们必须要获得所有可能的ids组合

... otherwise we necessarily have to get all the possible ids's combinations

import itertools as it
import pprint as pp

df2['ids_']   = df2.ids.apply(lambda l:l[:40])  # Let's make the bet that 40 ids will be enough to find the sum we want, avoiding memory error at the same time.
df2['combos'] = df2.ids_.apply(
    lambda l: list(it.chain.from_iterable(
        it.combinations(l, i + 1)
        for i in range(len(l))
    ))
)

pp.pprint(df2.combos[2]) # an illustration with the indexed-by-2 combinations (code `'xxx'`)
### [('128281',),
###  ('128282',),
###  ('128283',),
###  ('128284',),
###  ('128281', '128282'),
###  ('128281', '128283'),
###  ('128281', '128284'),
###  ('128282', '128283'),
###  ('128282', '128284'),
###  ('128283', '128284'),
###  ('128281', '128282', '128283'),
###  ('128281', '128282', '128284'),
###  ('128281', '128283', '128284'),
###  ('128282', '128283', '128284'),
###  ('128281', '128282', '128283', '128284')]

我们现在需要计算canceled值和order-这些组合所产生的和之间的所有距离.

We now need to compute all the distances between canceled values and order-sums that result from these combinations.

df2['distances'] = df2.apply(
    lambda r : {
        combo : abs(
            r.canceled - df.loc[
            df.code.isin([r.code]) & df.id.isin(combo),
            ('order',)
        ].sum()[0]) for combo in r.combos
    },
    axis = 1
)
pp.pprint(df2.distances[2])                                                                          
### {('128281',): 5.0,
###  ('128281', '128282'): 4.0,
###  ('128281', '128282', '128283'): 1.0,
###  ('128281', '128282', '128283', '128284'): 2.0,
###  ('128281', '128282', '128284'): 3.0,
###  ('128281', '128283'): 0.0,           #<--- this is the 'xxx'-combination we want
###  ('128281', '128283', '128284'): 1.0,
###  ('128281', '128284'): 4.0,
###  ('128282',): 10.0,
###  ('128282', '128283'): 5.0,
###  ('128282', '128283', '128284'): 4.0,
###  ('128282', '128284'): 9.0,
###  ('128283',): 6.0,
###  ('128283', '128284'): 5.0,
###  ('128284',): 10.0}

..现在我们可以隔离出想要的确切组合

.. and we can now isolate the exact combination(s) we want

default_minv        = [float('inf')]
df2['min_distance'] = df2.distances.apply(
    lambda ds : min(ds.values() or default_minv) # to avoid errors when ds.values() is empty
)
df2['summed_ids'] = df2.apply(
    lambda r : [
        c for c, d in r.distances.items()
        if d == r.min_distance
    ],
    axis = 1
)

print(df2.loc[:, ('code', 'canceled', 'orders_sum', 'min_distance', 'summed_ids')])                     
###   code  canceled  orders_sum  min_distance                                         summed_ids
### 0  cvd      20.0          55          35.0                                         [(11111,)]
### 1  eeS       5.0          14           0.0  [(11111,), (115236, 108586, 113472), (115236, ...
### 2  xxx      11.0          13           0.0                                 [(128281, 128283)]

i)如上所示,我已经将min_distance定义为不同的列,这仅仅是因为在单个列中包含不同/多种类型的对象不是一种好习惯,并且 ii)这种方法是通用的,因此,如果许多min_distance具有相同的min_distance,则您可以将ids的多个组合作为summed_ids ie . >


i) As you can see above, I have defined min_distance as a distinct column, simply because it is not a good practice to have different/multiple types of objects within a single column and ii) the approach is generalized so that you can have multiple combinations of ids as summed_ids, i.e. if many of them have the same min_distance.

[...]我还需要选择最可能的ID总计为被取消的值.

[...] I also need to select the most possible ids that sum up to the canceled value.

此后,这样做就像

cols_of_interest = ['code', 'canceled', 'orders_sum', 'direct_ids', 'summed_ids']
sub_df = df2.loc[
    (df2.min_distance==0) | df2.direct_ids.map(len), cols_of_interest
]
print(sub_df)                                                        
###   code  canceled  orders_sum direct_ids                                         summed_ids
### 1  eeS       5.0          14    [11111]  [(11111,), (115236, 108586, 113472), (115236, ...
### 2  xxx      11.0          13         []                                 [(128281, 128283)]


避免存储所有组合(无需像以前那样定义df2['combos']),您可以执行以下操作:


The avoid the storage of all the combinations (no need to define df2['combos'] as before), something you could do is:

df2['distances'] = df2.apply(
    lambda r : {
        combo : abs(
            r.canceled - df.loc[
            df.code.isin([r.code]) & df.id.isin(combo),
            ('order',)
        ].sum()[0]) for combo in it.chain.from_iterable(
            it.combinations(r.ids, i + 1)
            for i in range(len(r.ids))
        )
    },
    axis = 1
)


更新

由于我承认它开始成为 code-golf ,请考虑(紧随其后的strong> 整个 )代码


UPDATE

Because I admit that it started to become code-golf, consider the (entire) code that follows

import itertools as it

df2 = df.groupby('code').agg({
    'canceled' : 'first',
    'order'    : list,
    'id'       : list
}).reset_index().rename(
    columns={
        'id'    : 'ids',
        'order' : 'orders',
    }
)

df2['orders_sum'] = df2.orders.apply(sum)


df2['direct_ids'] = df2.apply(
    lambda r: [
        i for o, i in zip(r.orders, r.ids)
        if o == r.canceled
    ],
    axis = 1
)

def distances_computer(r):
    combos = it.chain.from_iterable(
        it.combinations(r.ids, i + 1)
        for i in range(len(r.ids))
    )
    distances_ = []
    for combo in combos:
        d = abs(
            r.canceled - df.loc[
            df.code.isin([r.code]) & df.id.isin(combo),
            ('order',)
        ].sum()[0])
        distances_.append((combo, d)) 
        if d == 0: # Iterations stops as soon as a zero-distance is found.
            break
    # Let's minimize the number of returned distances, keeping only the 10
    # smallest
    distances = sorted(distances_, key=lambda item:item[1])[:10] # Actually you may want to put `1` instead of `10`.
    return dict(distances)

df2['distances'] = df2.apply(
    distances_computer, axis = 1
)   


default_minv        = [float('inf')]
df2['min_distance'] = df2.distances.apply(
    lambda ds : min(ds.values() or default_minv) # to avoid errors when ds.values() is empty
)
df2['summed_ids'] = df2.apply(
    lambda r : [
        c for c, d in r.distances.items()
        if d == r.min_distance
    ],
    axis = 1
)

cols_of_interest = ['code', 'canceled', 'orders_sum', 'direct_ids', 'summed_ids']
sub_df = df2.loc[
    (df2.min_distance==0) | df2.direct_ids.map(len), cols_of_interest
]

这篇关于Python Pandas根据另一个列中的总数从另一个dataFrame中选择值的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!

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