pandas pivot_table 保持索引
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pandas pivot_table keep index
提问by Vincent Claes
i have a dataframe :
我有一个数据框：
day_bucket label numeric_value
0 2011-01-21 birds 4
1 2011-01-22 birds 0
2 2011-01-23 birds 7
3 2011-01-24 birds 3
I want to pivot this dataframe so that i have a column birdswith the values below it.
我想旋转此数据框，以便我有一列birds其下方的值。
pd.pivot_table(df, values='numeric_value', index='day_bucket',columns='label')
gives:
给出：
label birds
day_bucket
2011-01-21 4
2011-01-22 0
2011-01-23 7
2011-01-24 3
what should i do the keep the index? The result will look like:
我该怎么做才能保持索引？结果将如下所示：
day_bucket birds
0 2011-01-21 4
1 2011-01-22 0
2 2011-01-23 7
3 2011-01-24 3
回答by piRSquared
set_indexwith append
set_index和 append
df.set_index(['day_bucket', 'label'], append=True) \
.rename_axis([None, None, None]).squeeze().unstack()
回答by Vincent Claes
In the meantime, I also came up with a result
与此同时，我也想出了一个结果
pd.pivot_table(df, values='numeric_value',
index=[df.index.values,'day_bucket'],
,columns='label').reset_index('day_bucket')
label day_bucket mortality_birds
0 2011-01-21 4
1 2011-01-22 0
2 2011-01-23 7
3 2011-01-24 3
回答by Sean.H
just for supplement: this works fine, we can get:
仅供补充：这很好用，我们可以得到：
pt2 = pt.rename_axis(None, axis=1).reset_index()
print(pt2)
day_bucket birds
0 2011-01-21 4
1 2011-01-22 0
2 2011-01-23 7
3 2011-01-24 3
the dataframe used for it is:
用于它的数据框是：
df = pd.DataFrame({'day_bucket': ['2011-01-21', '2011-01-22', '2011-01-23', '2011-01-24'],
'label': ['birds', 'birds', 'birds', 'birds'],
'num_value': [4, 0, 7, 3]})
pt = pd.pivot_table(df,
values='num_value',
index='day_bucket',
columns='label',
aggfunc=np.sum)
print(pt, '\n')
label birds
day_bucket
2011-01-21 4
2011-01-22 0
2011-01-23 7
2011-01-24 3
