Fix py-pox build recipe (#14078)

* Fix py-pox build recipe

* PEP-8 fix

* Update package.py

* Apply suggestions from code review

Co-Authored-By: Adam J. Stewart <ajstewart426@gmail.com>

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

@@ -10,8 +10,9 @@ class PyPox(PythonPackage):
     """Utilities for filesystem exploration and automated builds."""
 
     homepage = "https://github.com/uqfoundation/pox"
-    url      = "https://pypi.io/packages/source/p/pox/pox-0.2.3.zip"
+    url      = "https://pypi.io/packages/source/p/pox/pox-0.2.5.tar.gz"
 
+    version('0.2.5', sha256='2b53fbdf02596240483dc2cb94f94cc21252ad1b1858c7b1c151afeec9022cc8')
     version('0.2.3', sha256='d3e8167a1ebe08ae56262a0b9359118d90bc4648cd284b5d10ae240343100a75')
     version('0.2.2', sha256='c0b88e59ef0e4f2fa4839e11bf90d2c32d6ceb5abaf01f0c8138f7558e6f87c1')
     version('0.2.1', sha256='580bf731fee233c58eac0974011b5bf0698efb7337b0a1696d289043b4fcd7f4')
@@ -19,3 +20,13 @@ class PyPox(PythonPackage):
     depends_on('python@2.5:2.8,3.1:')
 
     depends_on('py-setuptools@0.6:', type='build')
+
+    def url_for_version(self, version):
+        url = "https://pypi.io/packages/source/p/pox/"
+        if version >= Version('0.2.4'):
+            url += 'pox-{0}.tar.gz'
+        else:
+            url += 'pox-{0}.zip'
+
+        url = url.format(version)
+        return url