```python
import pandas as pd
data = pd.read_csv(r'D:\PycharmProjects\数据处理\DATA\fuel.csv')
data['date'] = pd.to_datetime(data['date'], format='%Y-%m-%d %H:%M:%S')
data.set_index('date', inplace=True) # 把时间列作为索引
bars = data.resample('3min').sum().dropna().reset_index() # 切分
print(bars)
bars.to_csv('fuel.csv', index=False)
划分为3min一个数据,求和后有[26593 rows x 2 columns]
但求平均有[9508 rows x 2 columns]
都是划分的3min,为什么出来的数据个数不一致
```