Updating value in column

Question

I would need to update some information on a column called Value:

I would like to add to Value 0.5 if Home has value 124. I am thinking of using .loc to select rows but I would need to understand how to update the value. My expected results should be

Value Home
12     123
30.5   124
21.5   124
21     99

Any tip is appreciated.

`df['Value'] = np.where(df['Home'] == 124, df['Value'] + 0.5, df['Value'])` — David Erickson, Oct 08 '20 at 01:12

score 4 · Accepted Answer · answered Oct 08 '20 at 01:11

4

df.loc[df['Home']==124, 'Value'] += .5

answered Oct 08 '20 at 01:11

Chris

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1

thank you to both. May I ask you if this solution works also with another condition based on a different column (for example if Property is > 20)? – still_learning Oct 08 '20 at 01:26
1

@still_learning sure: `df.loc[(df['Home']==124) & (df['Property'] > 20), 'Value']+=5` – Chris Oct 08 '20 at 01:38

score 2 · Answer 2 · edited Oct 08 '20 at 01:14

2

Use mask

mask = (df.Home == 124)
df.loc[mask,'Value'] = df.loc[mask,'Value'] + 0.5

edited Oct 08 '20 at 01:14

Chris

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answered Oct 08 '20 at 01:13

Sivaram Rasathurai

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Updating value in column

2 Answers2