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pandas update dataframe row with new value

Tags:

python

pandas

I have a text file which has been read into pandas by df1 = pandas.read_csv(r'fruits.txt', sep=',')

    item  freshness
0   apple    2.2
1   pear     0.0

and a series of calculations that would yield the result of apple = 2.3

Is it possible to do a pandas.update so that I can update the value of freshness for apple in the dataframe to 2.3?

like image 692
jake wong Avatar asked Apr 10 '16 14:04

jake wong

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1 Answers

IIUC you need loc:

apple = 2.3

print df['item'] == 'apple'
0     True
1    False
Name: item, dtype: bool

df.loc[df['item'] == 'apple', 'freshness'] = apple
print df
    item  freshness
0  apple        2.3
1   pear        0.0
like image 89
jezrael Avatar answered Sep 28 '22 07:09

jezrael
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