Python3用多线程替代for循环提升程序运行速度

[本文出自天外归云的博客园]

优化前后新老代码如下：

from git_tools.git_tool import get_collect_projects, QQNews_Git

from threading import Thread, Lock

import datetime

base_url = "http://git.xx.com"

project_members_commits_lang_info = {}

lock = Lock()

threads = []

'''

Author:zenkilan

'''

def count_time(func):

    def took_up_time(*args, **kwargs):

        start_time = datetime.datetime.now()

        ret = func(*args, **kwargs)

        end_time = datetime.datetime.now()

        took_up_time = (end_time - start_time).total_seconds()

        print(f"{func.__name__} execution took up time:{took_up_time}")

        return ret

    return took_up_time

def get_project_member_lang_code_lines(git, member, begin_date, end_date):

    global project_members_commits_lang_info

    global lock

    member_name = member["username"]

    r = git.get_user_info(member_name)

    if not r["id"]:

        return

    user_commits_lang_info = git.get_commits_user_lang_diff_between(r["id"], begin_date, end_date)

    if len(user_commits_lang_info) == 0:

        return

    lock.acquire()

    project_members_commits_lang_info.setdefault(git.project, dict())

    project_members_commits_lang_info[git.project][member_name] = user_commits_lang_info

    lock.release()

def get_project_lang_code_lines(project, begin_date, end_date):

    global threads

    git = QQNews_Git(project[1], base_url, project[0])

    project_members = git.get_project_members()

    if len(project_members) == 0:

        return

    for member in project_members:

        thread = Thread(target=get_project_member_lang_code_lines, args=(git, member, begin_date, end_date))

        threads.append(thread)

        thread.start()

@count_time

def get_projects_lang_code_lines(begin_date, end_date):

    """

    获取项目代码行语言相关统计——新方法（提升效率）

    应用多线程替代for循环

    并发访问共享外部资源

    :return:

    """

    global project_members_commits_lang_info

    global threads

    for project in get_collect_projects():

        thread = Thread(target=get_project_lang_code_lines, args=(project, begin_date, end_date))

        threads.append(thread)

        thread.start()

@count_time

def get_projects_lang_code_lines_old(begin_date, end_date):

    """

    获取项目代码行语言相关统计——老方法（耗时严重）

    使用最基本的思路进行编程

    双层for循环嵌套并且每层都包含耗时操作

    :return:

    """

    project_members_commits_lang_info = {}

    for project in get_collect_projects():

        git = QQNews_Git(project[1], base_url, project[0])

        project_members = git.get_project_members()

        user_commits_lang_info_dict = {}

        if len(project_members) == 0:

            continue

        for member in project_members:

            member_name = member["username"]

            r = git.get_user_info(member_name, debug=False)

            if not r["id"]:

                continue

            try:

                user_commits_lang_info = git.get_commits_user_lang_diff_between(r["id"], begin_date, end_date)

                if len(user_commits_lang_info) == 0:

                    continue

                user_commits_lang_info_dict[member_name] = user_commits_lang_info

                project_members_commits_lang_info[git.project] = user_commits_lang_info_dict

            except:

                pass

    return project_members_commits_lang_info

def test_results_equal(resultA, resultB):

    """

    测试方法

    :param resultA:

    :param resultB:

    :return:

    """

    print(resultA)

    print(resultB)

    assert len(str(resultA)) == len(str(resultB))

if __name__ == '__main__':

    from git_tools.config import begin_date, end_date

    get_projects_lang_code_lines(begin_date, end_date)

    for t in threads:

        t.join()

    old_result = get_projects_lang_code_lines_old(begin_date, end_date)

    test_results_equal(old_result, project_members_commits_lang_info)

老方法里外层for循环和内层for循环里均存在耗时操作：

1）git.get_project_members()

2）git.get_user_info(member_name, debug=False)

分两步来优化，先里后外或先外后里都行。用多线程替换for循环，并发共享外部资源，加锁避免写冲突。

测试结果通过，函数运行时间装饰器显示（单位秒）：

get_projects_lang_code_lines execution took up time:1.85294

get_projects_lang_code_lines_old execution took up time:108.604177

速度提升了约58倍