assign values to columns pandas dataframe

Question

I have a temporary dataframe temp (as shown below) sliced from a larger dataframe.

I appreciate it if help me to assign the item_price value of each row to a related column associated with model as shown below:

Note: original and larger dataframe contains brands, prices and models which some of the rows have a similar brand name with different model and price, so I slice those similar records into temp dataframe and try to assign price to related columns associated with model for each record.

Thanks in advance!

Ofek Glick · Accepted Answer · 2021-08-28T17:24:02.660

2

If I were you I would delete the columns 'Sedan', 'Sport' and 'SUV' and use pivot
In your case you would want to do the following:
Create a new Dataframe called df1 like so:

df1 = df.pivot(index='brand', columns='model', values='item_price')

And then join your original DataFrame df1 with df1.

df = df.join(df1, on='brand')

This will give you the result you are looking for.

edited Aug 28 '21 at 17:24

answered Aug 28 '21 at 16:17

Ofek Glick

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The resulting dataframe become reshaped based on the **model**, however it contains **NaN** value. for example index 317 has **NaN** value for SUV and Sport. – Homayoun Soleimani Aug 28 '21 at 16:37
As I've edited my answer, you can set `index` to 'brand' and now your resulting dataframe will be like you wanted it – Ofek Glick Aug 28 '21 at 16:46
After using reset_index(), it returns only the return dataframe with one record. columns are: ['brand', 'SUV', 'Sedan', 'Sport'], and values are ['BMW', 90.0, 78.0, 83.0]. – Homayoun Soleimani Aug 28 '21 at 17:05
It's important to keep other rows and columns for further process. – Homayoun Soleimani Aug 28 '21 at 17:07
Edited again, now it is exactly like your example. – Ofek Glick Aug 28 '21 at 17:25
Thanks a lot for your help and for introducing new methods to me. It works as I needed. – Homayoun Soleimani Aug 28 '21 at 19:48

score 0 · Answer 2 · answered Aug 28 '21 at 16:18

You can create a method that returns the value based on a condition like this:

I'm using df as the name of the dataframe, you can rename to temp.

def set_item_price(model):
  if model == "Sedan":
    return 78.00

  return 0

df["item_price"] = [
  set_item_price(a) for a in df['model']
]

assign values to columns pandas dataframe

2 Answers2