Iterating through a column and mapping values-CodePudding

Here is what I am trying to do. I want to substitute the values of this data frame.

For example. Bernard to be substituted as 1, and then Drake as 2 and so on and so forth. How to iterate through the column to write a function that can do the following.

CodePudding user response：

The function already exists -

Using that, we'd just assign a new column:

df = df.assign(codes=pd.factorize(df.name)[0]   1)

CodePudding user response：

IIUC

data = {
    'Name' : ['My Name', 'My Name', 'Your Name', 'Your Name'],
    'Date' : ['2022-01-01', '2022-02-01', '2022-01-01', '2022-02-01']
}
df = pd.DataFrame(data)
df['Count'] = df.groupby(['Name']).cumcount()   1
df

CodePudding user response：

You can use the built in category codes to achieve this:

df.Name.astype('category').cat.codes 1

CodePudding user response：

create a dictionary and the map

dict = {'bernard':1, 'drake':2, 'sansa':3}
df['code'] = df['name'].map(dict)

    name    date    code
0   bernard 01/11/2020  1
1   drake   01/11/2020  2
2   sansa   01/11/2020  3

is that what you're looking for?