import pandas as pd
def change_score(df):
df.loc['d', 'score'] = 11.5
return df
df1 = pd.DataFrame({'name': ['Tom', 'Jack', 'Steve', 'Ricky'], 'score': [85, 90, 87, 91]}, index=['a', 'b', 'c', 'd'])
df2 = pd.DataFrame({'name': ['Adam', 'Eve', 'Stark', 'Rogers'], 'score': [88, 92, 95, 97]}, index=['a', 'b', 'c', 'd'])
print(change_score(df1))
print(change_score(df2))