我想将数十亿的值(汇率)插入sqlite db文件。我想使用线程,因为它需要很多时间,但是线程池循环会多次执行相同的第n个元素。我在方法的开头有一条打印语句,它打印多次而不是一次。
pool = ThreadPoolExecutor(max_workers=2500)
def gen_nums(i, cur):
global x
print('row number', x, ' has started')
gen_numbers = list(mydata)
sql_data = []
for f in gen_numbers:
sql_data.append((f, i, mydata[i]))
cur.executemany('INSERT INTO numbers (rate, min, max) VALUES (?, ?, ?)', sql_data)
print('row number', x, ' has finished')
x += 1
with conn:
cur = conn.cursor()
for i in mydata:
pool.submit(gen_nums, i, cur)
pool.shutdown(wait=True)
输出为:
row number 1 has started
row number 1 has started
row number 1 has started
row number 1 has started
row number 1 has started
row number 1 has started
row number 1 has started
...