GroupBy

按發行人彙總2021年截至目前債券實際發行規模的統計

from pandas import Series,DataFrame
import pandas as pd
import pymysql

db = pymysql.connect(host='127.0.0.1',
                    port =3306,
                    user = 'root',
                    password = 'root',
                   database = 'jydb',charset='GBK'
 
)

sql = """SELECT MainCode,BondNature,Issuer,PlanIssueSize,ActualIssueSize FROM Bond_IssueNew where IssueDateStart>='2021-01-01"""

df = pd.read_sql(sql,db)
grouped = df['ActualIssueSize'].groupby(df['Issuer'])#按Issuer進行分組，並計算ActualIssueSize的和

df1 = grouped()
df1.to_excel('2.xlsx')

執行結果：

對分組進行迭代

from pandas import Series,DataFrame
import pandas as pd
import pymysql

db = pymysql.connect(host='127.0.0.1',
                    port =3306,
                    user = 'root',
                    password = 'root',
                   database = 'jydb',charset='GBK')

sql = """SELECT MainCode,BondNature,Issuer,PlanIssueSize,ActualIssueSize FROM Bond_IssueNew where IssueDateStart>='2021-01-01'
 
"""

df = pd.read_sql(sql,db)
for (k1,k2),group in df.groupby(['BondNature','Issuer']):
    print(k1,k2)
    print(group)

執行結果：