尝试将列设置为pandas数据帧中的索引时出错

import pandas as pd

# 创建示例数据帧
data = {'A': [1, 2, 3, 4],
        'B': [5, 6, 7, 8]}
df = pd.DataFrame(data)

# 尝试将列设置为索引
try:
    df.set_index('A', inplace=True)
except Exception as e:
    print("设置索引时出错:", e)

# 处理可能的错误情况
if 'A' in df.columns:
    if df['A'].duplicated().any():
        df.drop_duplicates(subset='A', inplace=True)
    if df['A'].isnull().any():
        df.dropna(subset='A', inplace=True)
    if df['A'].dtype == 'object':
        df['A'] = df['A'].astype(int)
    df.rename(columns={'A': 'New_A'}, inplace=True)

# 再次尝试将列设置为索引
df.set_index('New_A', inplace=True)