我有以下数据集

df = pd.DataFrame({
    'UID': [1, 1, 1, 2, 2, 2, 3, 3, 3],
    'Year': [2015, 2016, 2017, 2014, 2015, 2017, 2014, 2015, 2016],
    'Good?': [0, 1, 1, 0, 0, 1, 0, 1, 0]
})

对于每个UID，我试图找出第一个“良好？”值为1的年份值是什么，以及接下来的年份值满足条件“良好？”为1的年份值是什么。如果不满足条件，我想将该值指定为2017。
我似乎有一些问题的索引，因为它抛出一个'KeyError：######' -我想有些情况下我只有一个年份值，这会抛出一个错误。这是我目前得到的结果。

# Group the DataFrame by UID
groups = df.groupby('UID')

# Initialize an empty list to store the results
results = []

# Loop over each UID group
for uid, group in groups:
    # Find the first index with a Good value of 1
    first_good_index = group[group['Good?'] == 1].index[0]
    print(first_good_index)
    
    # Check if all following years have a Good value of 1
    if (group.loc[first_good_index+1:, 'Good?'] == 1).all():
        # If so, append the UID and the year of the first good row to the results list
        results.append((uid, group.loc[first_good_index, 'Year']))
    else:
        results.append((uid, 2017))

    
# Create a DataFrame from the results
results_df = pd.DataFrame(results, columns=['UID', 'First Good Year'])

# Print the results
print(results_df)

这些是预期的结果

results_df = pd.DataFrame({
    'UID': [1, 2, 3],
    'First Good Year': [2016, 2017, 2017],
})

results_df