import pandas as pd

data = {
    'number': [1, 2, 5, 2, 2, 5],
    'letter': ['A', 'B', 'D', 'D', 'D', 'D']
}
df = pd.DataFrame(data)

# Count the occurrences of each number in the "number" column
count_per_number = df['number'].value_counts()

# Filter the DataFrame by keeping only the rows where the number has multiple matches in the "letter" column
result_df = df[df['number'].isin(count_per_number[count_per_number > 1].index)]

print(result_df)

字符串
输出量：

number letter
1       2      B
3       2      D
4       2      D

型