CODEWITHSUNDEEP
pythonpandasdataframe
Youngjin Noh
Youngjin Noh

Reputation: 17

copy value from one column to another if condition is met in pandas

I have a dataframe:

df =

col1 Aciton1
1 A
2 B
3 C
1 C

I want to edit df, such that when the value of col1 is bigger than 1 , take the value from Action1.

So I will get:

col1 Aciton1 Previous_Aciton
1 A Initial Action
2 B A
3 C B
1 C Initial Action

Upvotes: 1

Views: 866

Answers (2)

keramat
keramat

Reputation: 4543

Use:

df = pd.DataFrame({'col1': [1,2,3], 'act1': ['A', 'B', 'C'], 'Previsou_Aciton':['G', 'H', 'I']})
temp = df[df['col1']>1].index
df['Previsou_Aciton'].loc[temp]=df.loc[[x-1 for x in temp]]['act1'].values

input df:

enter image description here

the result:

enter image description here

Upvotes: 0

jezrael
jezrael

Reputation: 862651

If there are no negative and 0 values and each group starting by 1 is possible use DataFrameGroupBy.shift:

df['Previsou_Aciton'] = df.groupby(df['col1'].eq(1).cumsum())['Aciton1'].shift(fill_value='Initail Action')
print (df)
   col1 Aciton1 Previsou_Aciton
0     1       A  Initail Action
1     2       B               A
2     3       C               B
3     1       C  Initail Action

Upvotes: 1

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