py-nltk: add new package (#16290)

var/spack/repos/builtin/packages/py-nltk/package.py

@@ -0,0 +1,23 @@
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+class PyNltk(PythonPackage):
+    """The Natural Language Toolkit (NLTK) is a Python package for
+    natural language processing."""
+
+    homepage = "https://www.nltk.org/"
+    url      = "https://pypi.io/packages/source/n/nltk/nltk-3.5.zip"
+
+    version('3.5', sha256='845365449cd8c5f9731f7cb9f8bd6fd0767553b9d53af9eb1b3abf7700936b35')
+
+    depends_on('python@3.5:', type=('build', 'run'))
+    depends_on('py-setuptools', type='build')
+    depends_on('py-click', type=('build', 'run'))
+    depends_on('py-regex', type=('build', 'run'))
+    depends_on('py-tqdm', type=('build', 'run'))
+
+    # May require additional third-party software:
+    # https://github.com/nltk/nltk/wiki/Installing-Third-Party-Software