3.py

import time
start_time = time.time()
print("开始时间为：",start_time)
list1 = []
for a in range(0,1000):
    for b in range(0,1000):
        list1.insert(0,0)
end_time = time.time()
print("结束时间为：",end_time)
result = end_time - start_time
print('总共',result)