Let's dive into numpy world

import numpy as np


arr1=list(range(1000000))
arr2=list(range(1000000,2000000))

#numpy
arr1_np = np.array(arr1)
arr2_np = np.array(arr2)

IOPub data rate exceeded.
The notebook server will temporarily stop sending output
to the client in order to avoid crashing it.
To change this limit, set the config variable
`--NotebookApp.iopub_data_rate_limit`.

Current values:
NotebookApp.iopub_data_rate_limit=1000000.0 (bytes/sec)
NotebookApp.rate_limit_window=3.0 (secs)

%%time
res=0
for a,b in zip(arr1,arr2):
    res+=(a*b)
res

CPU times: user 316 ms, sys: 27.9 ms, total: 343 ms
Wall time: 433 ms

833332333333500000

%%time
np.dot(arr1_np,arr2_np)

CPU times: user 2.19 ms, sys: 1.29 ms, total: 3.48 ms
Wall time: 16.2 ms

833332333333500000