Python pkg_resources 模块，get_provider() 实例源码

def _get_version_from_pkg_resources(self):
        """Obtain a version from pkg_resources or setup-time logic if missing.

        This will try to get the version of the package from the pkg_resources
        record associated with the package, and if there is no such record
        falls back to the logic sdist would use.
        """
        try:
            requirement = pkg_resources.Requirement.parse(self.package)
            provider = pkg_resources.get_provider(requirement)
            result_string = provider.version
        except pkg_resources.DistributionNotFound:
            # The most likely cause for this is running tests in a tree
            # produced from a tarball where the package itself has not been
            # installed into anything. Revert to setup-time logic.
            from pbr import packaging
            result_string = packaging.get_version(self.package)
        return SemanticVersion.from_pip_string(result_string)

def _get_version_from_pkg_resources(self):
        """Obtain a version from pkg_resources or setup-time logic if missing.

        This will try to get the version of the package from the pkg_resources
        record associated with the package, and if there is no such record
        falls back to the logic sdist would use.
        """
        # Lazy import because pkg_resources is costly to import so defer until
        # we absolutely need it.
        import pkg_resources
        try:
            requirement = pkg_resources.Requirement.parse(self.package)
            provider = pkg_resources.get_provider(requirement)
            result_string = provider.version
        except pkg_resources.DistributionNotFound:
            # The most likely cause for this is running tests in a tree
            # produced from a tarball where the package itself has not been
            # installed into anything. Revert to setup-time logic.
            from pbr import packaging
            result_string = packaging.get_version(self.package)
        return SemanticVersion.from_pip_string(result_string)

def _get_version_from_pkg_resources(self):
        """Obtain a version from pkg_resources or setup-time logic if missing.

        This will try to get the version of the package from the pkg_resources
        record associated with the package, and if there is no such record
        falls back to the logic sdist would use.
        """
        try:
            requirement = pkg_resources.Requirement.parse(self.package)
            provider = pkg_resources.get_provider(requirement)
            return provider.version
        except pkg_resources.DistributionNotFound:
            # The most likely cause for this is running tests in a tree
            # produced from a tarball where the package itself has not been
            # installed into anything. Revert to setup-time logic.
            from pbr import packaging
            return packaging.get_version(self.package)

def _get_version_from_pkg_resources(self):
        """Obtain a version from pkg_resources or setup-time logic if missing.

        This will try to get the version of the package from the pkg_resources
        record associated with the package, and if there is no such record
        falls back to the logic sdist would use.
        """
        try:
            requirement = pkg_resources.Requirement.parse(self.package)
            provider = pkg_resources.get_provider(requirement)
            result_string = provider.version
        except pkg_resources.DistributionNotFound:
            # The most likely cause for this is running tests in a tree
            # produced from a tarball where the package itself has not been
            # installed into anything. Revert to setup-time logic.
            from pbr import packaging
            result_string = packaging.get_version(self.package)
        return SemanticVersion.from_pip_string(result_string)

def test_redocjs_lib_is_copied(sphinxdocs):
    srcdir, outdir = sphinxdocs
    extdir = py.path.local(
        pkg_resources.get_provider('sphinxcontrib.redoc').module_path)

    assert outdir.join('_static', 'redoc.js').check()
    assert outdir.join('_static', 'redoc.js').computehash() \
        == extdir.join('redoc.js').computehash()

def get_yt_version():
    try:
        from yt.__hg_version__ import hg_version
        return hg_version
    except ImportError:
        pass
    import pkg_resources
    yt_provider = pkg_resources.get_provider("yt")
    path = os.path.dirname(yt_provider.module_path)
    version = get_git_version(path)
    if version is None:
        return version
    else:
        return version[:12].strip().decode('utf-8')

def __call__(self, opts):
        import pkg_resources
        yt_provider = pkg_resources.get_provider("yt")
        path = os.path.dirname(yt_provider.module_path)
        vstring = _print_installation_information(path)
        if vstring is not None:
            print("This installation CAN be automatically updated.")
            if opts.update_source:
                update_hg_or_git(path)
        elif opts.update_source:
            _print_failed_source_update()
        if vstring is not None and opts.outputfile is not None:
            open(opts.outputfile, "w").write(vstring)

def __call__(self, opts):
        import pkg_resources
        yt_provider = pkg_resources.get_provider("yt")
        path = os.path.dirname(yt_provider.module_path)
        vstring = _print_installation_information(path)
        if vstring is not None:
            print()
            print("This installation CAN be automatically updated.")
            update_hg_or_git(path)
        else:
            _print_failed_source_update(opts.reinstall)