feat(python): add license fields

pkg/python/packaging/parse.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"io"
 	"net/textproto"
+	"strings"
 
 	"golang.org/x/xerrors"
 
@@ -26,11 +27,31 @@ func (*Parser) Parse(r dio.ReadSeekerAt) ([]types.Library, []types.Dependency, e
 		return nil, nil, xerrors.Errorf("read MIME error: %w", err)
 	}
 
+	// "License-Expression" takes precedence as "License" is deprecated.
+	// cf. https://peps.python.org/pep-0639/#deprecate-license-field
+	var license string
+	if l := h.Get("License-Expression"); l != "" {
+		license = l
+	} else if l := h.Get("License"); l != "" {
+		license = l
+	} else {
+		for _, classifier := range h.Values("Classifier") {
+			if strings.HasPrefix(classifier, "License :: ") {
+				values := strings.Split(classifier, " :: ")
+				license = values[len(values)-1]
+				break
+			}
+		}
+	}
+	if license == "" && h.Get("License-File") != "" {
+		license = "file://" + h.Get("License-File")
+	}
+
 	return []types.Library{
 		{
 			Name:    h.Get("Name"),
 			Version: h.Get("Version"),
-			License: h.Get("License"),
+			License: license,
 		},
 	}, nil, nil
 }

pkg/python/packaging/parse_test.go

@@ -72,6 +72,39 @@ func TestParse(t *testing.T) {
 			input:   "testdata/invalid.json",
 			wantErr: true,
 		},
+		{
+			name:  "with License-Expression field",
+			input: "testdata/iniconfig-2.0.0.METADATA",
+			want: []types.Library{
+				{
+					Name:    "iniconfig",
+					Version: "2.0.0",
+					License: "MIT",
+				},
+			},
+		},
+		{
+			name:  "with an empty license field but with license in Classifier",
+			input: "testdata/zipp-3.12.1.METADATA",
+			want: []types.Library{
+				{
+					Name:    "zipp",
+					Version: "3.12.1",
+					License: "MIT License",
+				},
+			},
+		},
+		{
+			name:  "without licenses, but with a license file (a license in Classifier was removed)",
+			input: "testdata/networkx-3.0.METADATA",
+			want: []types.Library{
+				{
+					Name:    "networkx",
+					Version: "3.0",
+					License: "file://LICENSE.txt",
+				},
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

pkg/python/packaging/testdata/iniconfig-2.0.0.METADATA

@@ -0,0 +1,80 @@
+Metadata-Version: 2.1
+Name: iniconfig
+Version: 2.0.0
+Summary: brain-dead simple config-ini parsing
+Project-URL: Homepage, https://github.com/pytest-dev/iniconfig
+Author-email: Ronny Pfannschmidt <opensource@ronnypfannschmidt.de>, Holger Krekel <holger.krekel@gmail.com>
+License-Expression: MIT
+License-File: LICENSE
+Classifier: Development Status :: 4 - Beta
+Classifier: Intended Audience :: Developers
+Classifier: License :: OSI Approved :: MIT License
+Classifier: Operating System :: MacOS :: MacOS X
+Classifier: Operating System :: Microsoft :: Windows
+Classifier: Operating System :: POSIX
+Classifier: Programming Language :: Python :: 3
+Classifier: Programming Language :: Python :: 3 :: Only
+Classifier: Programming Language :: Python :: 3.7
+Classifier: Programming Language :: Python :: 3.8
+Classifier: Programming Language :: Python :: 3.9
+Classifier: Programming Language :: Python :: 3.10
+Classifier: Programming Language :: Python :: 3.11
+Classifier: Topic :: Software Development :: Libraries
+Classifier: Topic :: Utilities
+Requires-Python: >=3.7
+Description-Content-Type: text/x-rst
+
+iniconfig: brain-dead simple parsing of ini files
+=======================================================
+
+iniconfig is a small and simple INI-file parser module
+having a unique set of features:
+
+* maintains order of sections and entries
+* supports multi-line values with or without line-continuations
+* supports "#" comments everywhere
+* raises errors with proper line-numbers
+* no bells and whistles like automatic substitutions
+* iniconfig raises an Error if two sections have the same name.
+
+If you encounter issues or have feature wishes please report them to:
+
+    https://github.com/RonnyPfannschmidt/iniconfig/issues
+
+Basic Example
+===================================
+
+If you have an ini file like this:
+
+.. code-block:: ini
+
+    # content of example.ini
+    [section1] # comment
+    name1=value1  # comment
+    name1b=value1,value2  # comment
+
+    [section2]
+    name2=
+        line1
+        line2
+
+then you can do:
+
+.. code-block:: pycon
+
+    >>> import iniconfig
+    >>> ini = iniconfig.IniConfig("example.ini")
+    >>> ini['section1']['name1'] # raises KeyError if not exists
+    'value1'
+    >>> ini.get('section1', 'name1b', [], lambda x: x.split(","))
+    ['value1', 'value2']
+    >>> ini.get('section1', 'notexist', [], lambda x: x.split(","))
+    []
+    >>> [x.name for x in list(ini)]
+    ['section1', 'section2']
+    >>> list(list(ini)[0].items())
+    [('name1', 'value1'), ('name1b', 'value1,value2')]
+    >>> 'section1' in ini
+    True
+    >>> 'inexistendsection' in ini
+    False

pkg/python/packaging/testdata/networkx-3.0.METADATA

@@ -0,0 +1,132 @@
+Metadata-Version: 2.1
+Name: networkx
+Version: 3.0
+Summary: Python package for creating and manipulating graphs and networks
+Home-page: https://networkx.org/
+Author: Aric Hagberg
+Author-email: hagberg@lanl.gov
+Maintainer: NetworkX Developers
+Maintainer-email: networkx-discuss@googlegroups.com
+Project-URL: Bug Tracker, https://github.com/networkx/networkx/issues
+Project-URL: Documentation, https://networkx.org/documentation/stable/
+Project-URL: Source Code, https://github.com/networkx/networkx
+Keywords: Networks,Graph Theory,Mathematics,network,graph,discrete mathematics,math
+Platform: Linux
+Platform: Mac OSX
+Platform: Windows
+Platform: Unix
+Classifier: Development Status :: 5 - Production/Stable
+Classifier: Intended Audience :: Developers
+Classifier: Intended Audience :: Science/Research
+Classifier: Operating System :: OS Independent
+Classifier: Programming Language :: Python :: 3
+Classifier: Programming Language :: Python :: 3.8
+Classifier: Programming Language :: Python :: 3.9
+Classifier: Programming Language :: Python :: 3.10
+Classifier: Programming Language :: Python :: 3.11
+Classifier: Programming Language :: Python :: 3 :: Only
+Classifier: Topic :: Software Development :: Libraries :: Python Modules
+Classifier: Topic :: Scientific/Engineering :: Bio-Informatics
+Classifier: Topic :: Scientific/Engineering :: Information Analysis
+Classifier: Topic :: Scientific/Engineering :: Mathematics
+Classifier: Topic :: Scientific/Engineering :: Physics
+Requires-Python: >=3.8
+License-File: LICENSE.txt
+Provides-Extra: default
+Requires-Dist: numpy (>=1.20) ; extra == 'default'
+Requires-Dist: scipy (>=1.8) ; extra == 'default'
+Requires-Dist: matplotlib (>=3.4) ; extra == 'default'
+Requires-Dist: pandas (>=1.3) ; extra == 'default'
+Provides-Extra: developer
+Requires-Dist: pre-commit (>=2.20) ; extra == 'developer'
+Requires-Dist: mypy (>=0.991) ; extra == 'developer'
+Provides-Extra: doc
+Requires-Dist: sphinx (==5.2.3) ; extra == 'doc'
+Requires-Dist: pydata-sphinx-theme (>=0.11) ; extra == 'doc'
+Requires-Dist: sphinx-gallery (>=0.11) ; extra == 'doc'
+Requires-Dist: numpydoc (>=1.5) ; extra == 'doc'
+Requires-Dist: pillow (>=9.2) ; extra == 'doc'
+Requires-Dist: nb2plots (>=0.6) ; extra == 'doc'
+Requires-Dist: texext (>=0.6.7) ; extra == 'doc'
+Provides-Extra: extra
+Requires-Dist: lxml (>=4.6) ; extra == 'extra'
+Requires-Dist: pygraphviz (>=1.10) ; extra == 'extra'
+Requires-Dist: pydot (>=1.4.2) ; extra == 'extra'
+Requires-Dist: sympy (>=1.10) ; extra == 'extra'
+Provides-Extra: test
+Requires-Dist: pytest (>=7.2) ; extra == 'test'
+Requires-Dist: pytest-cov (>=4.0) ; extra == 'test'
+Requires-Dist: codecov (>=2.1) ; extra == 'test'
+
+NetworkX
+========
+
+.. image:: https://github.com/networkx/networkx/workflows/test/badge.svg?tag=networkx-3.0
+  :target: https://github.com/networkx/networkx/actions?query=branch%3Anetworkx-3.0
+
+.. image:: https://codecov.io/gh/networkx/networkx/branch/main/graph/badge.svg
+   :target: https://app.codecov.io/gh/networkx/networkx/branch/main
+
+.. image:: https://img.shields.io/github/labels/networkx/networkx/Good%20First%20Issue?color=green&label=Contribute%20&style=flat-square
+   :target: https://github.com/networkx/networkx/issues?q=is%3Aopen+is%3Aissue+label%3A%22Good+First+Issue%22
+
+
+NetworkX is a Python package for the creation, manipulation,
+and study of the structure, dynamics, and functions
+of complex networks.
+
+- **Website (including documentation):** https://networkx.org
+- **Mailing list:** https://groups.google.com/forum/#!forum/networkx-discuss
+- **Source:** https://github.com/networkx/networkx
+- **Bug reports:** https://github.com/networkx/networkx/issues
+- **Report a security vulnerability:** https://tidelift.com/security
+- **Tutorial:** https://networkx.org/documentation/latest/tutorial.html
+- **GitHub Discussions:** https://github.com/networkx/networkx/discussions
+
+Simple example
+--------------
+
+Find the shortest path between two nodes in an undirected graph:
+
+.. code:: pycon
+
+    >>> import networkx as nx
+    >>> G = nx.Graph()
+    >>> G.add_edge("A", "B", weight=4)
+    >>> G.add_edge("B", "D", weight=2)
+    >>> G.add_edge("A", "C", weight=3)
+    >>> G.add_edge("C", "D", weight=4)
+    >>> nx.shortest_path(G, "A", "D", weight="weight")
+    ['A', 'B', 'D']
+
+Install
+-------
+
+Install the latest version of NetworkX::
+
+    $ pip install networkx
+
+Install with all optional dependencies::
+
+    $ pip install networkx[all]
+
+For additional details, please see `INSTALL.rst`.
+
+Bugs
+----
+
+Please report any bugs that you find `here <https://github.com/networkx/networkx/issues>`_.
+Or, even better, fork the repository on `GitHub <https://github.com/networkx/networkx>`_
+and create a pull request (PR). We welcome all changes, big or small, and we
+will help you make the PR if you are new to `git` (just ask on the issue and/or
+see `CONTRIBUTING.rst`).
+
+License
+-------
+
+Released under the 3-Clause BSD license (see `LICENSE.txt`)::
+
+   Copyright (C) 2004-2023 NetworkX Developers
+   Aric Hagberg <hagberg@lanl.gov>
+   Dan Schult <dschult@colgate.edu>
+   Pieter Swart <swart@lanl.gov>