Use extend() for per_call_policies and per_retry_policies

[jiasli]

Refine #17340

For List Concatenation, using Add (+) is slower compared to INPLACE Add (+=) and extend():

Source: https://blog.finxter.com/python-list-concatenation-add-vs-inplace-add-vs-extend/

This PRs unifies the code for per_call_policies and per_retry_policies and only uses extend() for List Concatenation.

[jiasli]

for is the slowest.

import time

# Compare runtime of three methods
list_sizes = [i * 400000 for i in range(30)]
runtimes_1 = []  # Method 1: + Operator
runtimes_2 = []  # Method 2: += Operator
runtimes_3 = []  # Method 3: extend()
runtimes_4 = []  # Method 3: for
for size in list_sizes:
    to_add = list(range(size))

    # Get time stamps
    time_0 = time.time()
    lst = [1]
    lst = lst + to_add
    time_1 = time.time()
    lst = [1]
    lst += to_add
    time_2 = time.time()
    lst = [1]
    lst.extend(to_add)
    time_3 = time.time()
    lst = [1]
    for i in to_add:
        lst.append(i)
    time_4 = time.time()
    # Calculate runtimes
    runtimes_1.append((size, time_1 - time_0))
    runtimes_2.append((size, time_2 - time_1))
    runtimes_3.append((size, time_3 - time_2))
    runtimes_4.append((size, time_4 - time_3))
# Plot everything
import matplotlib.pyplot as plt
import numpy as np

runtimes_1 = np.array(runtimes_1)
runtimes_2 = np.array(runtimes_2)
runtimes_3 = np.array(runtimes_3)
runtimes_4 = np.array(runtimes_4)
print(runtimes_1)
print(runtimes_2)
print(runtimes_3)
print(runtimes_4)
plt.plot(runtimes_1[:, 0], runtimes_1[:, 1], label='Method 1: +')
plt.plot(runtimes_2[:, 0], runtimes_2[:, 1], label='Method 2: +=')
plt.plot(runtimes_3[:, 0], runtimes_3[:, 1], label='Method 3: extend()')
plt.plot(runtimes_4[:, 0], runtimes_4[:, 1], label='Method 4: for')
plt.xlabel('list size')
plt.ylabel('runtime (seconds)')
plt.legend()
plt.savefig('speed.png', dpi=400)
plt.show()

Code snippet from https://blog.finxter.com/python-list-concatenation-add-vs-inplace-add-vs-extend/

[xiangyan99]

(For your another PR), do we need list(per_call_policies) here?

[jiasli]

Not really. list.extend(iterable) by definition takes any iterable.

[ghost]

Hi @jiasli. Thank you for your interest in helping to improve the Azure SDK experience and for your contribution. We've noticed that there hasn't been recent engagement on this pull request. If this is still an active work stream, please let us know by pushing some changes or leaving a comment. Otherwise, we'll close this out in 7 days.

[ghost]

Hi @jiasli. Thank you for your contribution. Since there hasn't been recent engagement, we're going to close this out. Feel free to respond with a comment containing "/reopen" if you'd like to continue working on these changes. Please be sure to use the command to reopen or remove the "no-recent-activity" label; otherwise, this is likely to be closed again with the next cleanup pass.