Replace value from previous row in same column-CodePudding

I have a column in dataframe like this

test_data = pd.DataFrame({'Category':['Finance - Loan','1','2','3','4','Finance - Loan - Car','1','2', 'Car - Loan','1', '2', '3']})

How do i replace the number with the value before. The data type is string. Is there anyone can help?

CodePudding user response：

You can replace the numeric strings with NaN and use fillna() method

col = df['Category']
col[col.str.isnumeric()] = None
col = col.fillna(method='ffill')
df['Category'] = col

Result

    Category
0   Finance - Loan
1   Finance - Loan
2   Finance - Loan
3   Finance - Loan
4   Finance - Loan
5   Finance - Loan - Car
6   Finance - Loan - Car
7   Finance - Loan - Car
8   Car - Loan
9   Car - Loan
10  Car - Loan
11  Car - Loan

CodePudding user response：

Edit: bui answer is better.

import pandas as pd

test_data = pd.DataFrame(
{'Category': ['Finance - Loan', '1', '2', '3', '4', 'Finance - Loan - Car', '1', '2', 'Car - Loan', '1', '2', '3']})
lst = test_data['Category'].tolist()
test = []
for i in lst:
    if not i.isdigit():
        test.append(i)
    if i.isdigit():
        test.append(test[-1])
test_data['Category'] = test
print(test_data)