import pandas as pd
from sqlalchemy import create_engine
engine = create_engine('mysql+pymysql://root:root@localhost:3306/yoyo')
sql ="""select * from book_management_signin;"""
df = pd.read_sql(sql,engine)print(df.describe())print(df[df['id']<20])
import numpy as np
import pandas as pd
import numpy as np
day_data = np.random.normal(0,1,(500,507))
stock_list =["股票"+str(i)for i inrange(day_data.shape[0])]
date =["第"+str(i)+"天"for i inrange(day_data.shape[1])]
df = pd.DataFrame(day_data,index=stock_list,columns=date)print(df[df["第0天"]>0].sort_values("第0天",ascending=False))
2,使用复合逻辑运算符进行筛选(pandas的布尔索引)
import pandas as pd
from sqlalchemy import create_engine
engine = create_engine('mysql+pymysql://root:root@localhost:3306/yoyo')
sql ="""select * from role_info;"""
df = pd.read_sql(sql,engine)print(df.dtypes)print(df[(df[