load csv files into postgres db sqlalchemy
from numpy import genfromtxt
from time import time
from datetime import datetime
from sqlalchemy import Column, Integer, Float, Date
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
def Load_Data(file_name):
data = genfromtxt(file_name, delimiter=',', skip_header=1, converters={0: lambda s: str(s)})
return data.tolist()
Base = declarative_base()
class Price_History(Base):
#Tell SQLAlchemy what the table name is and if there's any table-specific arguments it should know about
__tablename__ = 'Price_History'
__table_args__ = {'sqlite_autoincrement': True}
#tell SQLAlchemy the name of column and its attributes:
id = Column(Integer, primary_key=True, nullable=False)
fid = Column(Integer, ForeignKey('Price_History.id'))
date = Column(Date)
opn = Column(Float)
hi = Column(Float)
lo = Column(Float)
close = Column(Float)
vol = Column(Float)
if __name__ == "__main__":
t = time()
#Create the database
engine = create_engine('sqlite:///csv_test.db')
Base.metadata.create_all(engine)
#Create the session
session = sessionmaker()
session.configure(bind=engine)
s = session()
try:
file_name = "t.csv" #sample CSV file used: http://www.google.com/finance/historical?q=NYSE%3AT&ei=W4ikVam8LYWjmAGjhoHACw&output=csv
data = Load_Data(file_name)
for i in data:
record = Price_History(**{
'date' : datetime.strptime(i[0], '%d-%b-%y').date(),
'opn' : i[1],
'hi' : i[2],
'lo' : i[3],
'close' : i[4],
'vol' : i[5]
})
s.add(record) #Add all the records
s.commit() #Attempt to commit all the records
except:
s.rollback() #Rollback the changes on error
finally:
s.close() #Close the connection
print "Time elapsed: " + str(time() - t) + " s."