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+:mod:`packaging.install` --- Installation tools
+===============================================
+
+.. module:: packaging.install
+ :synopsis: Download and installation building blocks
+
+
+Packaging provides a set of tools to deal with downloads and installation of
+distributions. Their role is to download the distribution from indexes, resolve
+the dependencies, and provide a safe way to install distributions. An operation
+that fails will cleanly roll back, not leave half-installed distributions on the
+system. Here's the basic process followed:
+
+#. Move all distributions that will be removed to a temporary location.
+
+#. Install all the distributions that will be installed in a temporary location.
+
+#. If the installation fails, move the saved distributions back to their
+ location and delete the installed distributions.
+
+#. Otherwise, move the installed distributions to the right location and delete
+ the temporary locations.
+
+This is a higher-level module built on :mod:`packaging.database` and
+:mod:`packaging.pypi`.
+
+
+Public functions
+----------------
+
+.. function:: get_infos(requirements, index=None, installed=None, \
+ prefer_final=True)
+
+ Return information about what's going to be installed and upgraded.
+ *requirements* is a string string containing the requirements for this
+ project, for example ``'FooBar 1.1'`` or ``'BarBaz (<1.2)'``.
+
+ .. XXX are requirements comma-separated?
+
+ If you want to use another index than the main PyPI, give its URI as *index*
+ argument.
+
+ *installed* is a list of already installed distributions used to find
+ satisfied dependencies, obsoleted distributions and eventual conflicts.
+
+ By default, alpha, beta and candidate versions are not picked up. Set
+ *prefer_final* to false to accept them too.
+
+ The results are returned in a dictionary containing all the information
+ needed to perform installation of the requirements with the
+ :func:`install_from_infos` function:
+
+ >>> get_install_info("FooBar (<=1.2)")
+ {'install': [<FooBar 1.1>], 'remove': [], 'conflict': []}
+
+ .. TODO should return tuple or named tuple, not dict
+ .. TODO use "predicate" or "requirement" consistently in version and here
+ .. FIXME "info" cannot be plural in English, s/infos/info/
+
+
+.. function:: install(project)
+
+
+.. function:: install_dists(dists, path, paths=None)
+
+ Safely install all distributions provided in *dists* into *path*. *paths* is
+ a list of paths where already-installed distributions will be looked for to
+ find satisfied dependencies and conflicts (default: :data:`sys.path`).
+ Returns a list of installed dists.
+
+ .. FIXME dists are instances of what?
+
+
+.. function:: install_from_infos(install_path=None, install=[], remove=[], \
+ conflicts=[], paths=None)
+
+ Safely install and remove given distributions. This function is designed to
+ work with the return value of :func:`get_infos`: *install*, *remove* and
+ *conflicts* should be list of distributions returned by :func:`get_infos`.
+ If *install* is not empty, *install_path* must be given to specify the path
+ where the distributions should be installed. *paths* is a list of paths
+ where already-installed distributions will be looked for (default:
+ :data:`sys.path`).
+
+ This function is a very basic installer; if *conflicts* is not empty, the
+ system will be in a conflicting state after the function completes. It is a
+ building block for more sophisticated installers with conflict resolution
+ systems.
+
+ .. TODO document typical value for install_path
+ .. TODO document integration with default schemes, esp. user site-packages
+
+
+.. function:: install_local_project(path)
+
+ Install a distribution from a source directory, which must contain either a
+ Packaging-compliant :file:`setup.cfg` file or a legacy Distutils
+ :file:`setup.py` script (in which case Distutils will be used under the hood
+ to perform the installation).
+
+
+.. function:: remove(project_name, paths=None, auto_confirm=True)
+
+ Remove one distribution from the system.
+
+ .. FIXME this is the only function using "project" instead of dist/release
+
+..
+ Example usage
+ --------------
+
+ Get the scheme of what's gonna be installed if we install "foobar":