CODEWITHSUNDEEP
pythonpandaspandas-groupby
user6882757
user6882757

Reputation:

Groupby pandas throwing ValueError: Grouper and axis must be same length

I have csv below

ID,PR_No,PMO,PRO,REV,COST
111,111,AB,MA,2575,2575
111,111,AB,MA,-1137,-1137
112,112,CD,KB,1134,3334
111,111,AB,MA,100,100

Output as below

ID,PR_No,PMO,PRO,REV,COST
111,111,AB,MA,1538,1538
112,112,CD,KB,1134,3334

1538=2575-1137+100

My code is throwing values error

df_n = df.groupby([['ID','PR_No','PMO','PRO']]).agg({'REV':sum,'COST':sum})

Upvotes: 3

Views: 6389

Answers (2)

rkoots
rkoots

Reputation: 213

Try with some agg or sum function it will work...

df_n = df.groupby([......])[....].sum()

Upvotes: -1

jezrael
jezrael

Reputation: 862661

Remove nested [] for list of columns names:

df_n = df.groupby(['ID','PR_No','PMO','PRO']).agg({'REV':sum,'COST':sum})
print (df_n)
                    REV  COST
ID  PR_No PMO PRO            
111 111   AB  MA   1538  1538
112 112   CD  KB   1134  3334

Because same aggregate function is possible create list after groupby with .sum:

df_n = df.groupby(['ID','PR_No','PMO','PRO'])['REV','COST'].sum()

ValueError: Grouper and axis must be same length

What does it mean?

If run with sample data it working, because length of nested list is same like length of sample data:

df_n = df.groupby([['ID','PR_No','PMO','PRO']]).agg({'REV':sum,'COST':sum})
print (df_n)
        REV  COST
ID     2575  2575
PMO    1134  3334
PRO     100   100
PR_No -1137 -1137

If create list with duplicates it aggregate sample data:

df_n = df.groupby([['ID','ID','PRO','PRO']]).agg({'REV':sum,'COST':sum})
print (df_n)
      REV  COST
ID   1438  1438
PRO  1234  3434

But if length is different it failed: 

print (df)
    ID  PR_No PMO PRO   REV  COST
0  111    111  AB  MA  2575  2575
1  111    111  AB  MA -1137 -1137
2  112    112  CD  KB  1134  3334
3  111    111  AB  MA   100   100
4  111    111  AB  MA   100   100 <- added new row

df_n = df.groupby([['ID','ID','PRO','PRO']]).agg({'REV':sum,'COST':sum})
print (df_n)

ValueError: Grouper and axis must be same length

Upvotes: 5

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