import pandas as pd
import numpy as np
df = pd.DataFrame({'Index': ['1', '2', '5', '7', '8', '9', '10'], 'Vals': [
    1, 2, 3, 4, np.nan, np.nan, 5]})
df['Index'] = df['Index'].astype(int)
clean_data = pd.DataFrame({'Index': list(range(1, 11))})
result = clean_data.merge(df, on='Index', how='outer')
Pandas DataFrame с непрерывным индексом