Add a value to a column in data frame all rows at once :Python

Question

I have following data from df

   proid  sku  qty 
0  p009  SKPK  0.0  
1  p009  SKKP  2.0  
2  p008  SKPK  0.0  
3  p008  SKC1  4.0  
4  p008  SKKP  0.0

To qty column i want to add value to 'qty' based on value in 'sku'. the value are present as follows

starterkit = {"SKKP":4,'SKP1':3,'SKP1':3,'SKPK':1,'SKC1':1 }

want to do something like

if df.sku == 'SKKP' df.qty += starterkit['SKKP']

Resulting data frame should be

   proid  sku  qty 
0  p009  SKPK  1.0  
1  p009  SKKP  6.0  
2  p008  SKPK  1.0  
3  p008  SKC1  5.0  
4  p008  SKKP  4.0

jezrael · Accepted Answer · 2018-05-12T16:56:28.360

1

Use map:

starterkit = {"SKKP":4,'SKP1':3,'SKP1':3,'SKPK':1,'SKC1':1 }
df.qty += df.sku.map(starterkit)
print (df)
  proid   sku  qty
0  p009  SKPK  1.0
1  p009  SKKP  6.0
2  p008  SKPK  1.0
3  p008  SKC1  5.0
4  p008  SKKP  4.0

edited May 12 '18 at 16:56

answered May 12 '18 at 16:54

jezrael

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1

but starter kit values are based on another column values in data frame – ila May 12 '18 at 16:56

score 0 · Answer 2 · answered May 12 '18 at 16:54

0

You can use pd.Series.map:

df['qty'] += df['sku'].map(starterkit)

This is an example of a vectorised calculation. A principle benefit of using pandas is the ability to perform such calculations without resorting to Python-level loops.

answered May 12 '18 at 16:54

jpp

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Add a value to a column in data frame all rows at once :Python

2 Answers2