i am using python. i have a dataframe with string column “description”. in these strings i have things like: “п. 5.6.2 ГОСТ 2.114-2016”, “п. 4.1 ГОСТ 2.102-2013”, “п.5 ГОСТ Р 51672-2000” and so on. i want to remove them

I tried this code:

import pandas as pd
import re

# Sample DataFrame
data = {'description': ["п. 5.6.2 ГОСТ 2.114-2016",
                        "п. 4.1 ГОСТ 2.102-2013",
                        "п.5 ГОСТ Р 51672-2000"]}

df = pd.DataFrame(data)

# Define the regex pattern to match the specified format
pattern = r'п.s*d+(?:.d+)*s*ГОСТ(?:s*Р)?s*d+(?:-d+)*'

# Remove the matched patterns from the 'description' column
df['description'] = df['description'].apply(lambda x: re.sub(pattern, '', x))

print(df)

but result is:

              description
0               .114-2016
1               .102-2013
2                     

what am is doing wrong?