Python Dependency Manager Companion

========================================= Package search and install specifications ========================================= Conda supports the following specifications for ``conda search`` and ``conda install``. Package search ============== ``conda search`` for a specific package or set of packages can be accomplished in several ways. This section includes information on the standard specification and the use of key-value pairs. Standard specification ---------------------- .. figure:: ../../img/conda_search.png :width: 100% **channel** (Optional) Can either be a channel name or URL. Channel names may include letters, numbers, dashes, and underscores. **subdir** (Optional) A subdirectory of a channel. Many subdirs are used for architectures, but this is not required. Must have a channel and backslash preceding it. For example: ``main/noarch`` **name** (Required) Package name. May include the ``*`` wildcard. For example, ``*py*`` returns all packages that have "py" in their names, such as "numpy", "pytorch", "python", etc. **version** (Optional) Package version. May include the ``*`` wildcard or a version range(s) in single quotes. For example: ``numpy=1.17.*`` returns all numpy packages with a version containing "1.17." and ``numpy>1.17,<1.19.2`` returns all numpy packages with versions greater than 1.17 and less than 1.19.2. **build** (Optional) Package build name. May include the ``*`` wildcard. For example, ``numpy 1.17.3 py38*`` returns all version 1.17.3 numpy packages with a build name that contains the text "py38". Key-value pairs --------------- Package searches can also be performed using what is called "key-value pair notation", which has different rules than the :ref:`Standard specification` example image. The search below will return the same list of packages as the standard specification. .. code-block:: none $ conda search "numpy[channel=conda-forge, subdir=linux-64, version=1.17.*, build=py38*]" This notation supports the following key-value pairs: .. program-output:: python -c 'import conda.models.match_spec as M; print("-", "\n- ".join([f"{field:20} # validated via {M._implementors.get(field, M.ExactStrMatch).__name__}" for field in sorted(M.MatchSpec.FIELD_NAMES)]))' :shell: Key-value pair notation can be used at the same time as standard notation. .. code-block:: none $ conda search "conda-forge::numpy=1.17.3[subdir=linux-64, build=py38*]" .. warning:: Any search values using the key-value pair notation will override values in the rest of the search string. For example, ``conda search numpy 1.17.3[version=1.19.2]`` will return packages with the version ``1.19.2``. Package installation ==================== When you're installing packages, conda recommends being as concrete as possible. Using ``*`` wildcards and version ranges during an install will most likely cause a conflict. However, ``*`` wildcards can still be helpful in an install command when used sparingly. Installing with wildcards ------------------------- Let's say you are working on a project that requires version 2.3 of a package. If you upgrade to 2.4 or 3.0, your project will break. You're also using an environment file to create your environment. In the version ``2.3.1``, ``2`` is the major version, ``3`` is the minor version, and ``1`` is the patch. Patches typically contain bug fixes, so if you want to keep version ``2.3`` in your environment without updating to ``2.4`` or ``3.0``, but want to take advantage of any bug fixes, using ``2.3.*`` in your environment file would be helpful to you. Concrete install example ------------------------ Let's take the search from the :ref:`Package search` section. .. code-block:: none $ conda search "conda-forge/linux-64::numpy 1.17.* py38*" This returns the following: .. code-block:: none Loading channels: done # Name Version Build Channel numpy 1.17.3 py38h95a1406_0 conda-forge numpy 1.17.5 py38h18fd61f_1 conda-forge numpy 1.17.5 py38h95a1406_0 conda-forge You can then choose a specific version and build, if necessary, and edit your ``conda install`` command accordingly. .. code-block:: none $ conda install "conda-forge/linux-64::numpy 1.17.5 py38h95a1406_0"