diff options
Diffstat (limited to 'Doc/library/packaging.pypi.simple.rst')
-rw-r--r-- | Doc/library/packaging.pypi.simple.rst | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/Doc/library/packaging.pypi.simple.rst b/Doc/library/packaging.pypi.simple.rst new file mode 100644 index 0000000..ea5edca --- /dev/null +++ b/Doc/library/packaging.pypi.simple.rst @@ -0,0 +1,157 @@ +:mod:`packaging.pypi.simple` --- Crawler using the PyPI "simple" interface +========================================================================== + +.. module:: packaging.pypi.simple + :synopsis: Crawler using the screen-scraping "simple" interface to fetch info + and distributions. + + +`packaging.pypi.simple` can process Python Package Indexes and provides +useful information about distributions. It also can crawl local indexes, for +instance. + +You should use `packaging.pypi.simple` for: + + * Search distributions by name and versions. + * Process index external pages. + * Download distributions by name and versions. + +And should not be used for: + + * Things that will end up in too long index processing (like "finding all + distributions with a specific version, no matters the name") + + +API +--- + +.. class:: Crawler + + +Usage Exemples +--------------- + +To help you understand how using the `Crawler` class, here are some basic +usages. + +Request the simple index to get a specific distribution +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Supposing you want to scan an index to get a list of distributions for +the "foobar" project. You can use the "get_releases" method for that. +The get_releases method will browse the project page, and return +:class:`ReleaseInfo` objects for each found link that rely on downloads. :: + + >>> from packaging.pypi.simple import Crawler + >>> crawler = Crawler() + >>> crawler.get_releases("FooBar") + [<ReleaseInfo "Foobar 1.1">, <ReleaseInfo "Foobar 1.2">] + + +Note that you also can request the client about specific versions, using version +specifiers (described in `PEP 345 +<http://www.python.org/dev/peps/pep-0345/#version-specifiers>`_):: + + >>> client.get_releases("FooBar < 1.2") + [<ReleaseInfo "FooBar 1.1">, ] + + +`get_releases` returns a list of :class:`ReleaseInfo`, but you also can get the +best distribution that fullfil your requirements, using "get_release":: + + >>> client.get_release("FooBar < 1.2") + <ReleaseInfo "FooBar 1.1"> + + +Download distributions +^^^^^^^^^^^^^^^^^^^^^^ + +As it can get the urls of distributions provided by PyPI, the `Crawler` +client also can download the distributions and put it for you in a temporary +destination:: + + >>> client.download("foobar") + /tmp/temp_dir/foobar-1.2.tar.gz + + +You also can specify the directory you want to download to:: + + >>> client.download("foobar", "/path/to/my/dir") + /path/to/my/dir/foobar-1.2.tar.gz + + +While downloading, the md5 of the archive will be checked, if not matches, it +will try another time, then if fails again, raise `MD5HashDoesNotMatchError`. + +Internally, that's not the Crawler which download the distributions, but the +`DistributionInfo` class. Please refer to this documentation for more details. + + +Following PyPI external links +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The default behavior for packaging is to *not* follow the links provided +by HTML pages in the "simple index", to find distributions related +downloads. + +It's possible to tell the PyPIClient to follow external links by setting the +`follow_externals` attribute, on instantiation or after:: + + >>> client = Crawler(follow_externals=True) + +or :: + + >>> client = Crawler() + >>> client.follow_externals = True + + +Working with external indexes, and mirrors +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The default `Crawler` behavior is to rely on the Python Package index stored +on PyPI (http://pypi.python.org/simple). + +As you can need to work with a local index, or private indexes, you can specify +it using the index_url parameter:: + + >>> client = Crawler(index_url="file://filesystem/path/") + +or :: + + >>> client = Crawler(index_url="http://some.specific.url/") + + +You also can specify mirrors to fallback on in case the first index_url you +provided doesnt respond, or not correctly. The default behavior for +`Crawler` is to use the list provided by Python.org DNS records, as +described in the :PEP:`381` about mirroring infrastructure. + +If you don't want to rely on these, you could specify the list of mirrors you +want to try by specifying the `mirrors` attribute. It's a simple iterable:: + + >>> mirrors = ["http://first.mirror","http://second.mirror"] + >>> client = Crawler(mirrors=mirrors) + + +Searching in the simple index +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +It's possible to search for projects with specific names in the package index. +Assuming you want to find all projects containing the "distutils" keyword:: + + >>> c.search_projects("distutils") + [<Project "collective.recipe.distutils">, <Project "Distutils">, <Project + "Packaging">, <Project "distutilscross">, <Project "lpdistutils">, <Project + "taras.recipe.distutils">, <Project "zerokspot.recipe.distutils">] + + +You can also search the projects starting with a specific text, or ending with +that text, using a wildcard:: + + >>> c.search_projects("distutils*") + [<Project "Distutils">, <Project "Packaging">, <Project "distutilscross">] + + >>> c.search_projects("*distutils") + [<Project "collective.recipe.distutils">, <Project "Distutils">, <Project + "lpdistutils">, <Project "taras.recipe.distutils">, <Project + "zerokspot.recipe.distutils">] |