学习日记-2019529

Flask脚本服务搭建、基于上下文环境的处理、Python从列表中随机抽取若干元素、Python中format格式化输出、Python多进程

【来源】https://www.u3v3.com/

学习日记 2019/5/29

Flask脚本服务搭建

flasky.py

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import os from dotenv import load_dotenv dotenv_path = os.path.join(os.path.dirname(__file__), '.env') if os.path.exists(dotenv_path): load_dotenv(dotenv_path) COV = None if os.environ.get('FLASK_COVERAGE'): import coverage COV = coverage.coverage(branch=True, include='app/*') COV.start() import sys import click from flask_migrate import Migrate, upgrade from app import create_app, db from app.models import User, Follow, Role, Permission, Post, Comment app = create_app(os.getenv('FLASK_CONFIG') or 'default') migrate = Migrate(app, db) def (): return dict(db=db, User=User, Follow=Follow, Role=Role, Permission=Permission, Post=Post, Comment=Comment) @app.cli.command() @click.option('--coverage/--no-coverage', default=False, help='Run tests under code coverage.') def test(coverage): """Run the unit tests.""" if coverage and not os.environ.get('FLASK_COVERAGE'): import subprocess os.environ['FLASK_COVERAGE'] = '1' sys.exit(subprocess.call(sys.argv)) import unittest tests = unittest.TestLoader().discover('tests') unittest.TextTestRunner(verbosity=2).run(tests) if COV: COV.stop() COV.save() print('Coverage Summary:') COV.report() basedir = os.path.abspath(os.path.dirname(__file__)) covdir = os.path.join(basedir, 'tmp/coverage') COV.html_report(directory=covdir) print('HTML version: file://%s/index.html' % covdir) COV.erase() @app.cli.command() @click.option('--length', default=25, help='Number of functions to include in the profiler report.') @click.option('--profile-dir', default=None, help='Directory where profiler data files are saved.') def profile(length, profile_dir): """Start the application under the code profiler.""" from werkzeug.contrib.profiler import ProfilerMiddleware app.wsgi_app = ProfilerMiddleware(app.wsgi_app, restrictions=[length], profile_dir=profile_dir) app.run() @app.cli.command() def deploy(): """Run deployment tasks.""" upgrade() # create or update user roles Role.insert_roles() # ensure all users are following themselves User.add_self_follows() if __name__ == '__main__': app.cli()

运行文件

python flasky.py

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(microvenv) [root@iz2ze8rern8nx1sglo8ub1z microblog]# python flasky.py Usage: flasky.py [OPTIONS] COMMAND [ARGS]... Options: --help Show this message and exit. Commands: deploy Run deployment tasks. profile Start the application under the code... test Run the unit tests.#新添加的内容

python flasky.py test

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(microvenv) [root@iz2ze8rern8nx1sglo8ub1z microblog]# python flasky.py test te 大专栏  学习日记-2019529st_password_setter (test_user_model.UserModelTestCase) ... ok ---------------------------------------------------------------------- Ran 1 test in 0.447s OK

基于上下文环境的处理

在 create_app内做Flask相关的初始化，将这部分资源处理置于独立的模块中, 使用的时候直接引入, 在模块第一次引入的时候就完成了资源的连接处理, 但总有一些还是需要运行前要执行的内容, 比如应用参数设置。

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def create_app(config_name): app = Flask(__name__) app.config.from_object(config[config_name]) config[config_name].init_app(app) bootstrap.init_app(app) mail.init_app(app) moment.init_app(app) db.init_app(app) login_manager.init_app(app) pagedown.init_app(app) if app.config['SSL_REDIRECT']: from flask_sslify import SSLify sslify = SSLify(app) from .main import main as main_blueprint app.register_blueprint(main_blueprint) from .auth import auth as auth_blueprint app.register_blueprint(auth_blueprint, url_prefix='/auth') from .api import api as api_blueprint app.register_blueprint(api_blueprint, url_prefix='/api/v1') return app

Python从列表中随机抽取若干元素

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import random x = [283,238,46,57,82,976] random.choice(x) random.sample(x,3) #从某个范围内获取若干个 random.sample(range(100000),30) #选取随机字符 random.choice('abcdrfgsfffgr') #生成随机整数 random.randint(100,200) #生成随机偶数 random.randrange(0,99,2) #生成0-1随机浮点数 random.random()

Python中format格式化输出

通过key名填充字符

1	print('My Name is {name},Age is {age}'.format(name=name,age=age))

通过字典的方式作参数传递

1 2	params = {'name':name,'age':age} print('My Name is {name},Age is {age}'.format(**params))

将tuple作为可变参数传递特性

1 2	params=('Tony',18) print('My Name is {0},Age is {1},And Your Age is {1}'.format(*params))

字符对齐

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print('{:>10},{:>10}'.format('tony',18))#左对齐 #右对齐< #居中对齐^

数字格式化

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#十进制转 #二进制 print('{:b}'.format(x)) #八进制 print('{:o}'.format(x)) #十六进制 print('{:x}'.format(x))

浮点数精度控制

1 2	pi = 3.1415926 print('{:.2f}'.format(pi))#保留两位小数3.14

三层{}可以转义

1	print('{{{0:.2f}}}'.format(pi))#{3.14}

Python多进程

• 进程创建

unix下使用fork方式创建子进程

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Process 24896 start ... This is Father process,And Its child pid is 24897 This is child process and my pid is 24897,my father process is 1 #子进程fork的结果总是0，可以用来作为区分父子进程的标志

变量在多进程之间并没有什么影响

windows下实现多进程用到了multiprocessing

pro = Process(target=pro_do,args=("test","dev"))

pro.start()

是否阻塞方式执行，如果有则阻塞，否则非阻塞

pro.join()

可以通过Pool进程池创建多个进程，可以指定启动的子进程数量

• 进程间通信

父进程可以指定子进程执行的方法及参数，达到父进程向子进程单项通信

子进程可以通过Queue方式向父进程通信write_queue，read_queue

两个进程间的通信可以使用Pipe形式send_pipe，recv_pipe