如何使水平轴通过原点？

import numpy as np
import matplotlib.pyplot as plt

rateList=[0,0.08,.1,.12,.15,.175,.225,.25,.275,.3,.325,.35]

list1=[-316.8,-424,-2.8,622,658,400,83,16.8,0]
NPV_Profile1=[np.npv(x,list1) for x in rateList]

list2=[-496,-760,84,1050.4,658,400,83,16.8,0]
NPV_Profile2=[np.npv(x,list2) for x in rateList]

plt.plot(rateList,NPV_Profile1,rateList,NPV_Profile2)

plt.show()

问题...

我试图通过SQLAlchemy连接到MSSql服务器.这是我的代码与假凭证(显然不是我真正的凭据).

代码...

credentials = {
'username'  : 'SPOTTER_xyz_ACC',
'password'  : '123Goodbye2016!@#',
'host'      : 'MARYLQLT01',
'database'  : 'LRS_DUS',
'port'      : '1560'}

connect_url = sqlalchemy.engine.url.URL(
    'mssql+pyodbc',
    username=credentials['username'],
    password=credentials['password'],
    host=credentials['host'],
    port=credentials['port'],
    query=dict(service_name=credentials['database']))

engine = create_engine(connect_url)
connection=engine.connect()

这是我得到的.pyodbc错误.

(pyodbc.Error) ('IM002', '[IM002] [Microsoft][ODBC Driver Manager] Data source
name not found and no default driver specified (0) (SQLDriverConnect)')

额外细节

但是,这是奇怪的...我如果做一个pyodbc连接并使用Pandas.read_sql,那么我可以没有错误地获取数据.所以我不明白为什么我得到'pyodbc'错误????

connection=pyodbc.connect(\
                          'Driver={SQL Server}; \
                          Server=MARYLQLT01; \
                          Database=LRS_DUS; \
                          UID=SPOTTER_xyz_ACC; \
                          PWD=123Goodbye2016!@#')

stmt='select * from PD_SC_All'
df=pd.read_sql(stmt,connection)

然后我可以看到数据帧.

那么,为什么(pyodbc.Error)我尝试连接SQLAlchemy时会遇到什么？

系统信息

Windows 7 …