Question

每当我查询我的SQL数据库以创建一个pandas df时，我总是得到行数列。我试过了：

df.drop(df.columns[[0]], axis=1, inplace=True)

但它会忽略该列，并删除我在查询中请求的第一列数据。所以我留下了从0开始的一列行号。无论我使用SQLAlchemy还是只使用Pyodbc，都会发生这种情况。

我的数据框看起来像

   | action| employee_number|part_number|time_stamp
0  |Add/Sub| 001841         |F151519FGL |2015-10-01
1  |Remove | 001997         |P088001DFL |2015-10-01
2  |Add/Sub| 001243         |-F151517DDL|2015-10-01
........................................................
50 |Add/Sub| 001458         |-1A0021049 |2015-10-01

我想将0和随后的所有数字删除到50+（特别是因为这都是写入Excel，额外的行数似乎是多余的）。

供参考，我的完整代码如下：

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import scoped_session,sessionmaker
from sqlalchemy import (Column, Integer, String, Boolean, ForeignKey, DateTime, Sequence, Float)
from sqlalchemy import create_engine
import pandas as pd
import openpyxl

##Needed in order to get SQL query properly formatted ***SHOULD BE CHANGED LATER****
pd.core.format.header_style = None 
pd.core.format.number_format = None 
#######################################################################################

##Takes sqlalchemy query and a list of columns, returns a dataframe.
def data_frame(query, columns):
    def make_row(x):
        return dict([(c, getattr(x, c)) for c in columns]) 
    return pd.DataFrame([make_row(x) for x in query])
############################################################################################

#####Creates Engine, Named Session(Currently Not Scoped), Declarative Base############################  
engine = create_engine('mssql+pyodbc://u:pass@Server/TableName?driver=SQL Server', echo=False)
Session = sessionmaker(bind=engine)
session = Session()
Base = declarative_base()



###########Class Name, __tablename__ is equal to table's name in db but we are specifying all column names & formats with at least one primary key######################
class Tranv(Base):
    __tablename__ = "Transactions"

    part_number = Column(String(20), primary_key=True)
    time_stamp = Column(String(20))
    employee_number = Column(String(6))
    action = Column(String(100))    

###Creating a variable with session query for specific Class Name  with filter (not filter_by which allows for extra operators)##############
newvarv = session.query(Tranv).filter_by(employee_number='001841').filter_by(time_stamp='2015-10-01 10:49:53.230')

###Uses data_frame function with input of session query variable name, and extra within [] the specified class must be included###############
dfx = data_frame(newvarv, [c.name for c in Tranv.__table__.columns])
##dfx.drop(dfx.columns[[0]], axis=1, inplace=True)
###Where I'm writing file to
writer = pd.ExcelWriter('C:\\Users\\grice\\Desktop\\Auto_Scrap_Report\\testy.xlsx')
###Formatting of any date times
writer.date_format = None
writer.datetime_format = None

###Actually writing the data to the .xlsx and saving
dfx.to_excel(writer, sheet_name='Sheet1')
writer.save()

从SQLAlchemy中的SQL查询中删除行号列

0 个答案: