在sqlalchemy中获取表的列的总和

Question

我有两个python文件：

1.create_account.py 2.run_sums.py

我想使用sum_balance函数从帐户表中获取列余额的总和。

但是，每次我运行run_sums.py时，总是出现错误：

“'int'对象不可调用”。我的编码有什么问题吗？

我对sqlalchemy很新鲜。

create_account.py：

import time
import random
from db_connect import get_conn

conn = get_conn().raw_connection()
cursor = conn.cursor()

cursor.execute("DROP TABLE IF EXISTS account")
cursor.execute("""
CREATE TABLE account(
    id INT NOT NULL GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
    branch INT NOT NULL,
    balance FLOAT NOT NULL)
""")

for i in xrange(0, 100000):
    account = random.randint(1, 20)
    balance = round(random.uniform(0, 100000), 2)
    cursor.execute("""INSERT INTO account VALUES (DEFAULT, %d,%f)""" % (account, balance))

conn.commit()

run_sums.py：

import argparse
from sqlalchemy.orm import sessionmaker
import time
from db_connect import get_conn
from sqlalchemy import *
from create_account import account

parser = argparse.ArgumentParser()
parser.add_argument('S', type = int, help = 'number of sums')
parser.add_argument('I', help = 'isolation level')
args = parser.parse_args()

## Execute a sum query and return the results
def sum_balance(sess):
    ## 1. Execute a query that sum the balance of all accounts.
    ## 2. Fetch the result and return it. 
    acc = account()
    sum_balance = sess.query(func.sum(acc.balance))
    return sum_balance

## Create S sums operations
def S_sums(sess, S):
    sums = []
    start = time.time()

    for i in xrange(0, S):
        while True:
            try:
                sum = sum_balance(sess)
                sums.append(sum)
            except Exception as e:
                print e
                continue
            break

    stop = time.time()
    return sums, stop-start

## Create the engine and run the sums
engine = get_conn()
Session = sessionmaker(bind=engine.execution_options(isolation_level=args.I, autocommit=True))
sess = Session()
sums, time = S_sums(sess, args.S)
print sums