Problems while replacing values in pandas dataframe?

Question

I have the following pandas dataframe:

In:

df = pd.DataFrame({'Fruits':['this should be a pinneapple', 
                              'this should be an apple', 
                              'this should be a tomato', 'this should 3 grapes',
                             'this should be an orange',
                              'this should be an 01',
                             'this should be an 02']})

df

Out:

    Fruits
0   this should be a pinneapple
1   this should be an apple
2   this should be a tomato
3   this should 3 grapes
4   this should be an orange
5   this should be an 01
6   this should be an 02

I would like to replace all the fruits with an id (e.g. 01 to nn). For this I tried with pandas replace function:

df['Fruits'] = df['Fruits'].replace(['pinneapple', 'apple', 'tomato', 'grapes', 'orange'],\
                                                                      ['01', '02', '03', '04', '05'])

However, when I do the above assignment nothing is done to the column I am interested to tweak. Thus, how can I replace each word for a predefined number?.

jezrael · Accepted Answer · 2017-02-18 19:49:36Z

3

You can use parameter regex=True in Series.replace:

df['Fruits'] = df['Fruits'].replace(['pinneapple', 'apple', 'tomato', 'grapes', 'orange'],\
                                    ['01', '02', '03', '04', '05'], regex=True)
print (df)
                 Fruits
0   this should be a 01
1  this should be an 02
2   this should be a 03
3      this should 3 04
4  this should be an 05
5  this should be an 01
6  this should be an 02

You can also use list comprehension for codes:

fruits = ['pinneapple', 'apple', 'tomato', 'grapes', 'orange']
codes = [str(i + 1).zfill(2) for i, c in enumerate(fruits)]
print (codes)
['01', '02', '03', '04', '05']

df['Fruits'] = df['Fruits'].replace(fruits,codes, regex=True)
print (df)

                 Fruits
0   this should be a 01
1  this should be an 02
2   this should be a 03
3      this should 3 04
4  this should be an 05
5  this should be an 01
6  this should be an 02

edited Feb 18, 2017 at 19:49

answered Feb 18, 2017 at 19:41

jezrael

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1 Comment

tumbleweed Over a year ago

Thanks for the help jez!

Mohamad Ibrahim · Accepted Answer · 2017-02-18 19:42:00Z

1

try resetting the value using the following:

df['Fruits'] =  pd.DataFrame()

then assign the new values again

answered Feb 18, 2017 at 19:42

Mohamad Ibrahim

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