为flask创建扩展

为flask创建扩展

对于flask的扩展我们已经很熟悉了,例如flask-corf等
其实从根本来说flask的扩展就是程序包。一些是为flask 增加功能,另一些是将一些功能附加到flask上

扩展的命名

命名要以flask开头加上你的功能扩展 比如本次的例子就是flask-slowlogger 就是用来记录慢相应日志的

创建规范的项目目录

为了规范化一个可以公共使用的项目你可以从这里导入一个通用的模版文件
https://github.com/pypa/sampleproject

目录文件介绍

编写扩展类,扩展的入口

class SlowLogger(object):
    def __init__(self,app):
        self.app = app
        self.logger = logging.getLogger("flask-limiter")
        self.enabled = "enabled"
        self.start = 0
        if app is not None:
            self.init_app(app)
        self.start = time.time()

    #提供的默认配置方法,可以在构造工厂中使用
    def init_app(self, app, **kwargs):
        #注册扩展
        app.extensions["slowlogger"] = self
        #设定默认配置文件
        app.config.setdefault('slowlogger_enable', False)
        app.config.setdefault("slowlogger_timeout",1)
        #通过请求钩子来区分
        self.app.before_request(self.__init_time)
        self.app.teardown_request(self.__log)

    def __init_time(self):
        self.start = time.time()


    def __log(self, *args):
        now = time.time()
        if self.app.config["slowlogger_timeout"]<= now \
                and \
            self.app.config["slowlogger_enable"] == True:

            self.app.logger.debug('Request: %s consumed %f s' % (request.url, now-self.start))
    #使用装饰器方式
    def log_entry(self, func):
        # app = self.app or current_app
        @wraps(func)
        def decorator(*args, **kwargs):
            start = time.time()
            # 记录请求开始
            self.app.logger.debug(f'Start request call: {request.url}')
            ret = func(*args, **kwargs)
            # 记录请求结束
            self.app.logger.debug(f'Finish request call: {request.url}')
            duration = time.time() - start
            # 记录请求所耗时长
            self.app.logger.debug(f'Request: {request.url} consumed {duration}')
            return ret

        return decorator

使用你的扩展

在本样例中可以选择通过全局配置开启全局的慢响应日志
或者通过装饰器方法在需要的接口上开启慢响应记录

打包你的扩展

创建setup.py

在setup 中填入设置项目

"""A setuptools based setup module.

See:
https://packaging.python.org/guides/distributing-packages-using-setuptools/
https://github.com/pypa/sampleproject
"""

# Always prefer setuptools over distutils
from setuptools import setup, find_packages
import pathlib

here = pathlib.Path(__file__).parent.resolve()

# Get the long description from the README file
long_description = (here / 'README.md').read_text(encoding='utf-8')

# Arguments marked as "Required" below must be included for upload to PyPI.
# Fields marked as "Optional" may be commented out.

setup(
    # This is the name of your project. The first time you publish this
    # package, this name will be registered for you. It will determine how
    # users can install this project, e.g.:
    #
    # $ pip install sampleproject
    #
    # And where it will live on PyPI: https://pypi.org/project/sampleproject/
    #
    # There are some restrictions on what makes a valid project name
    # specification here:
    # https://packaging.python.org/specifications/core-metadata/#name
    name='flask_slowlogger',  # Required

    # Versions should comply with PEP 440:
    # https://www.python.org/dev/peps/pep-0440/
    #
    # For a discussion on single-sourcing the version across setup.py and the
    # project code, see
    # https://packaging.python.org/en/latest/single_source_version.html
    version='0.0.1',  # Required

    # This is a one-line description or tagline of what your project does. This
    # corresponds to the "Summary" metadata field:
    # https://packaging.python.org/specifications/core-metadata/#summary
    description='log slow query',  # Optional

    # This is an optional longer description of your project that represents
    # the body of text which users will see when they visit PyPI.
    #
    # Often, this is the same as your README, so you can just read it in from
    # that file directly (as we have already done above)
    #
    # This field corresponds to the "Description" metadata field:
    # https://packaging.python.org/specifications/core-metadata/#description-optional
    long_description=long_description,  # Optional

    # Denotes that our long_description is in Markdown; valid values are
    # text/plain, text/x-rst, and text/markdown
    #
    # Optional if long_description is written in reStructuredText (rst) but
    # required for plain-text or Markdown; if unspecified, "applications should
    # attempt to render [the long_description] as text/x-rst; charset=UTF-8 and
    # fall back to text/plain if it is not valid rst" (see link below)
    #
    # This field corresponds to the "Description-Content-Type" metadata field:
    # https://packaging.python.org/specifications/core-metadata/#description-content-type-optional
    long_description_content_type='text/markdown',  # Optional (see note above)

    # This should be a valid link to your project's main homepage.
    #
    # This field corresponds to the "Home-Page" metadata field:
    # https://packaging.python.org/specifications/core-metadata/#home-page-optional
    url='https://github.com/lzxcloud/flask_slowlogger',  # Optional

    # This should be your name or the name of the organization which owns the
    # project.
    author='AizawaNozomi',  # Optional

    # This should be a valid email address corresponding to the author listed
    # above.
    author_email='lzxcloud@gmail.com',  # Optional

    # Classifiers help users find your project by categorizing it.
    #
    # For a list of valid classifiers, see https://pypi.org/classifiers/
    classifiers=[  # Optional
        # How mature is this project? Common values are
        #   3 - Alpha
        #   4 - Beta
        #   5 - Production/Stable
        'Development Status :: 3 - Alpha',

        # Indicate who your project is intended for
        'Intended Audience :: Developers',
        'Topic :: Software Development :: Build Tools',

        # Pick your license as you wish
        'License :: OSI Approved :: MIT License',

        # Specify the Python versions you support here. In particular, ensure
        # that you indicate you support Python 3. These classifiers are *not*
        # checked by 'pip install'. See instead 'python_requires' below.
        'Programming Language :: Python :: 3',
        'Programming Language :: Python :: 3.6',
        'Programming Language :: Python :: 3.7',
        'Programming Language :: Python :: 3.8',
        'Programming Language :: Python :: 3.9',
        'Programming Language :: Python :: 3 :: Only',
    ],

    # This field adds keywords for your project which will appear on the
    # project page. What does your project relate to?
    #
    # Note that this is a list of additional keywords, separated
    # by commas, to be used to assist searching for the distribution in a
    # larger catalog.
    keywords='sample, setuptools, development',  # Optional

    # When your source code is in a subdirectory under the project root, e.g.
    # `src/`, it is necessary to specify the `package_dir` argument.
    package_dir={'': 'flask_slowlogger'},  # Optional

    # You can just specify package directories manually here if your project is
    # simple. Or you can use find_packages().
    #
    # Alternatively, if you just want to distribute a single Python file, use
    # the `py_modules` argument instead as follows, which will expect a file
    # called `my_module.py` to exist:
    #
    #   py_modules=["my_module"],
    #
    packages=find_packages(where='src'),  # Required

    # Specify which Python versions you support. In contrast to the
    # 'Programming Language' classifiers above, 'pip install' will check this
    # and refuse to install the project if the version does not match. See
    # https://packaging.python.org/guides/distributing-packages-using-setuptools/#python-requires
    python_requires='>=3.6, <4',

    # This field lists other packages that your project depends on to run.
    # Any package you put here will be installed by pip when your project is
    # installed, so they must be valid existing projects.
    #
    # For an analysis of "install_requires" vs pip's requirements files see:
    # https://packaging.python.org/en/latest/requirements.html
    install_requires=['Flask'],  # Optional

    # List additional groups of dependencies here (e.g. development
    # dependencies). Users will be able to install these using the "extras"
    # syntax, for example:
    #
    #   $ pip install sampleproject[dev]
    #
    # Similar to `install_requires` above, these must be valid existing
    # projects.
    extras_require={  # Optional
        'dev': ['check-manifest'],
        'test': ['coverage'],
    },

    # If there are data files included in your packages that need to be
    # installed, specify them here.
    package_data={  # Optional
        'sample': ['package_data.dat'],
    },

    # Although 'package_data' is the preferred approach, in some case you may
    # need to place data files outside of your packages. See:
    # http://docs.python.org/distutils/setupscript.html#installing-additional-files
    #
    # In this case, 'data_file' will be installed into '<sys.prefix>/my_data'
    data_files=[('my_data', ['data/data_file'])],  # Optional

    # To provide executable scripts, use entry points in preference to the
    # "scripts" keyword. Entry points provide cross-platform support and allow
    # `pip` to create the appropriate form of executable for the target
    # platform.
    #
    # For example, the following would provide a command called `sample` which
    # executes the function `main` from this package when invoked:
    entry_points={  # Optional
        'console_scripts': [
            'sample=sample:main',
        ],
    },

    # List additional URLs that are relevant to your project as a dict.
    #
    # This field corresponds to the "Project-URL" metadata fields:
    # https://packaging.python.org/specifications/core-metadata/#project-url-multiple-use
    #
    # Examples listed include a pattern for specifying where the package tracks
    # issues, where the source is hosted, where to say thanks to the package
    # maintainers, and where to support the project financially. The key is
    # what's used to render the link text on PyPI.
    project_urls={  # Optional
        'Bug Reports': 'https://github.com/pypa/sampleproject/issues',
        'Funding': 'https://donate.pypi.org',
        'Say Thanks!': 'http://saythanks.io/to/example',
        'Source': 'https://github.com/pypa/sampleproject/',
    },
)

打包文件
python3 setup.py sdist bdist_wheel

从哪里获得flask的扩展

https://pypi.org/search/?c=Framework+%3A%3A+Flask

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