#读取数据
import pandas as pd
data = pd.read_csv('police.csv')
 
#将stop_date转化为datetime的格式的dataframe，存到stop_datetime
data['stop_datetime'] = pd.to_datetime(data.stop_date')

data_new = pd.to_datetime('2006-01-01')
data['time_d'] = time_new - data.stop_datetime
data['time_d'].head()

data.stop_datetime.dt.year.value_counts()
data.stop_datetime.dt.month.value_counts()

#提取年
data['year'] = data.stop_datetime.dt.year
data['year'].head()
 
#提取月份
data['month'] = data.stop_datetime.dt.month
data['month'].head()
 
#提取日
data['day'] = data.stop_datetime.dt.day
data['day'].head()

data['stop_time_datetime'] = pd.to_datetime(data.stop_time)
data.groupby(data.stop_time_datetime.dt.hour).drugs_related_stop.sum().plot()