Drop Python 2. Modernize notices. Format code

Signed-off-by: Philippe Ombredanne <[email protected]>

Author: pombredanne

NOTICE

@@ -2,7 +2,8 @@
 # Copyright (c) nexB Inc. and others.
 # SPDX-License-Identifier: Apache-2.0
 #
-# Visit https://aboutcode.org and https://github.com/nexB/license-expression for support and download.
+# Visit https://aboutcode.org and https://github.com/nexB/license-expression
+# for support and download.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.

README.rst

@@ -2,9 +2,9 @@
 license-expression
 ==================
 
-license-expression is a small utility library to parse, compare, simplify and normalize
-license expressions (e.g. SPDX license expressions) using boolean logic such as:
-`GPL-2.0 or later WITH Classpath Exception AND MIT`.
+license-expression is a comprehensive utility library to parse, compare,
+simplify and normalize license expressions (such as SPDX license expressions)
+using boolean logic like in: `GPL-2.0 or later WITH Classpath Exception AND MIT`.
 
 See also for details:
 https://spdx.org/sites/cpstandard/files/pages/files/spdxversion2.1.pdf#page=95&zoom=auto
@@ -135,6 +135,7 @@ Development
 ===========
 
 * Checkout a clone from https://github.com/nexB/license-expression.git
-* Then run ``./configure`` (or ``configure.bat``) and then ``source bin/activate``. This will
-  install all vendored dependencies in a local virtualenv, including development deps.
+* Then run ``./configure`` (or ``configure.bat``) and then ``source bin/activate``.
+  This will install all vendored dependencies in a local virtualenv, including
+  development deps.
 * To run the tests, run ``py.test -vvs``

src/license_expression/__init__.py

@@ -1,19 +1,10 @@
 #
-# license-expression is a free software tool from nexB Inc. and others.
-# Visit https://github.com/nexB/license-expression for support and download.
-#
 # Copyright (c) nexB Inc. and others. All rights reserved.
-# http://nexb.com and http://aboutcode.org
-#
-# This software is licensed under the Apache License version 2.0.
+# SPDX-License-Identifier: Apache-2.0
+# See http://www.apache.org/licenses/LICENSE-2.0 for the license text.
+# See https://github.com/nexB/license-expression for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
 #
-# You may not use this software except in compliance with the License.
-# You may obtain a copy of the License at: http://apache.org/licenses/LICENSE-2.0
-# Unless required by applicable law or agreed to in writing, software distributed
-# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
-# CONDITIONS OF ANY KIND, either express or implied. See the License for the
-# specific language governing permissions and limitations under the License.
-
 """
 This module defines a mini language to parse, validate, simplify, normalize and
 compare license expressions using a boolean logic engine.
@@ -27,15 +18,15 @@
 The main entry point is the Licensing object.
 """
 
+import itertools
+import re
+import string
 from collections import defaultdict
 from collections import deque
 from collections import namedtuple
 from copy import copy
 from copy import deepcopy
 from functools import total_ordering
-import itertools
-import re
-import string
 
 import boolean
 from boolean import Expression as LicenseExpression

src/license_expression/_pyahocorasick.py

@@ -1,36 +1,29 @@
 # -*- coding: utf-8 -*-
+#
+# SPDX-License-Identifier: LicenseRef-scancode-public-domain
+# See https://github.com/nexB/license-expression for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
+#
 """
-Aho-Corasick string search algorithm.
+Aho-Corasick string search algorithm in pure Python
 
 Original Author: Wojciech Muła, [email protected]
 WWW            : http://0x80.pl
 License        : public domain
 
-Modified for use in the license_expression library:
+This is the pure Python Aho-Corasick automaton from pyahocorasick modified for
+use in the license_expression library for advanced tokenization:
+
  - add support for unicode strings.
  - case insensitive search using sequence of words and not characters
  - improve returned results with the actual start,end and matched string.
  - support returning non-matched parts of a string
 """
-
-from __future__ import absolute_import
-from __future__ import print_function
-from __future__ import unicode_literals
-
 from collections import deque
 from collections import OrderedDict
 import logging
 import re
 
-# Python 2 and 3 support
-try:
-    # Python 2
-    unicode
-    str = unicode  # NOQA
-except NameError:
-    # Python 3
-    unicode = str  # NOQA
-
 TRACE = False
 
 logger = logging.getLogger(__name__)
@@ -109,7 +102,7 @@ def add(self, tokens_string, value=None):
         provided value, typically a Token object. If a value is not provided,
         the tokens_string is used as value.
 
-        A tokens_string is any unicode string. It will be tokenized when added
+        A tokens_string is any string. It will be tokenized when added
         to the Trie.
         """
         if self._converted:
@@ -326,7 +319,12 @@ def iter(self, tokens_string, include_unmatched=False, include_space=False):
                 if include_unmatched:
                     n = len(token_string)
                     start_pos = end_pos - n + 1
-                    tok = Token(start_pos, end_pos, tokens_string[start_pos: end_pos + 1], None)
+                    tok = Token(
+                        start=start_pos,
+                        end=end_pos,
+                        string=tokens_string[start_pos: end_pos + 1],
+                        value=None
+                    )
                     if TRACE:
                         logger_debug('  unmatched tok:', tok)
                     yield tok

tests/test__pyahocorasick.py

@@ -1,4 +1,8 @@
 # -*- coding: utf-8 -*-
+#
+# SPDX-License-Identifier: LicenseRef-scancode-public-domain
+# See https://github.com/nexB/license-expression for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
 
 """
 Tests for Aho-Corasick string search algorithm.

tests/test_license_expression.py

@@ -1,22 +1,15 @@
-# license-expression is a free software tool from nexB Inc. and others.
-# Visit https://github.com/nexB/license-expression for support and download.
 #
-# Copyright (c)  nexB Inc. and others. All rights reserved.
-# http://nexb.com  and http://aboutcode.org
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+# See http://www.apache.org/licenses/LICENSE-2.0 for the license text.
+# See https://github.com/nexB/license-expression for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
 #
-# This software is licensed under the Apache License version 2.0.
-#
-# You may not use this software except in compliance with the License.
-# You may obtain a copy of the License at: http://apache.org/licenses/LICENSE-2.0
-# Unless required by applicable law or agreed to in writing, software distributed
-# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
-# CONDITIONS OF ANY KIND, either express or implied. See the License for the
-# specific language governing permissions and limitations under the License.
 
+import sys
 from collections import namedtuple
 from unittest import TestCase
 from unittest.case import expectedFailure
-import sys
 
 from boolean.boolean import PARSE_UNBALANCED_CLOSING_PARENS
 from boolean.boolean import PARSE_INVALID_SYMBOL_SEQUENCE