CODEWITHSUNDEEP
pythonpandasdataframepivot-tablemulti-index
Jiamei
Jiamei

Reputation: 445

Anyway to reorder pivot table columns in Python?

Suppose I have a pivot table like this:

import pandas as pd

d = {'Col_A': [1,2,3,3,3,4,9,9,10,11], 
     'Col_B': ['A','K','E','E','H','A','J','A','L','A'],
     'Value1':[648,654,234,873,248,45,67,94,180,120],
     'Value2':[180,120,35,654,789,34,567,21,235,83]
    }

df = pd.DataFrame(data=d)
df_pvt = pd.pivot_table(df,values=['Value1','Value2'], index='Col_A', columns='Col_B', aggfunc=np.sum).fillna(0)
df_pvt

enter image description here

What I want to achieve is to set an order for Col_B (Highlighted) so that the outputs of Value1 and Value2 would display in this order E, J, A, K, L, H.

Upvotes: 1

Views: 2154

Answers (1)

sammywemmy
sammywemmy

Reputation: 28644

Convert col_B to a categorical before reshaping:

(df.astype({'Col_B' : pd.CategoricalDtype(['E', 'J', 'A', 'K', 'L', 'H'], ordered = True)})
   .pivot_table(values=['Value1','Value2'], 
                index='Col_A', 
                columns='Col_B', 
                aggfunc=np.sum)
)
      Value1                         Value2
Col_B      E   J    A    K    L    H      E    J    A    K    L    H
Col_A
1          0   0  648    0    0    0      0    0  180    0    0    0
2          0   0    0  654    0    0      0    0    0  120    0    0
3       1107   0    0    0    0  248    689    0    0    0    0  789
4          0   0   45    0    0    0      0    0   34    0    0    0
9          0  67   94    0    0    0      0  567   21    0    0    0
10         0   0    0    0  180    0      0    0    0    0  235    0
11         0   0  120    0    0    0      0    0   83    0    0    0

To reorder the columns, you can reindex, with the relevant keyword arguments:

(df.astype({'Col_B' : pd.CategoricalDtype(['E', 'J', 'A', 'K', 'L', 'H'], ordered = True)})
   .pivot_table(values=['Value1','Value2'], 
                index='Col_A', 
                columns='Col_B', 
                aggfunc=np.sum)
  .reindex(['Value2', 'Value1'], axis = 1, level = 0)
)

      Value2                          Value1
Col_B      E    J    A    K    L    H      E   J    A    K    L    H
Col_A
1          0    0  180    0    0    0      0   0  648    0    0    0
2          0    0    0  120    0    0      0   0    0  654    0    0
3        689    0    0    0    0  789   1107   0    0    0    0  248
4          0    0   34    0    0    0      0   0   45    0    0    0
9          0  567   21    0    0    0      0  67   94    0    0    0
10         0    0    0    0  235    0      0   0    0    0  180    0
11         0    0   83    0    0    0      0   0  120    0    0    0

Upvotes: 2

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