Added method to fetch project versions using PyPi API, removed hardco…

…ded versions in tests.

l2tdevtools/download_helpers/pypi.py

@@ -3,6 +3,7 @@
 
 from __future__ import unicode_literals
 
+import json
 import re
 
 # pylint: disable=wrong-import-position
@@ -78,6 +79,38 @@ def _GetAvailableVersions(self, version_strings):
 
     return available_versions
 
+  def GetLatestVersionWithAPI(self, project_name, version_definition):
+    """Retrieves the latest version for a given project using the PyPi API.
+
+    Args:
+      project_name (str): name of the project.
+      version_definition (ProjectVersionDefinition): project version definition
+          or None.
+
+    Returns:
+      str: latest version number or None if not available.
+    """
+    earliest_version = None
+    latest_version = None
+
+    if version_definition:
+      earliest_version = version_definition.GetEarliestVersion()
+      if earliest_version and earliest_version[0] == '==':
+        return '.'.join(earliest_version[1:])
+
+      latest_version = version_definition.GetLatestVersion()
+
+    pypi_url = 'https://pypi.org/pypi/{0:s}/json'.format(project_name)
+    page_content = self.DownloadPageContent(pypi_url)
+
+    api_data = json.loads(page_content)
+    releases = api_data.get('releases', {})
+    version_strings = releases.keys()
+    available_versions = self._GetAvailableVersions(version_strings)
+
+    return self._GetLatestVersion(
+        earliest_version, latest_version, available_versions)
+
   def GetLatestVersion(self, unused_project_name, version_definition):
     """Retrieves the latest version number for a given project name.
 

tests/download_helpers/pypi.py

@@ -30,6 +30,9 @@ def testGetLatestVersion(self):
 
     latest_version = download_helper.GetLatestVersion(self._PROJECT_NAME, None)
 
+    latest_version = download_helper.GetLatestVersionWithAPI(
+        self._PROJECT_NAME, None)
+
     self.assertEqual(latest_version, self._PROJECT_VERSION)
 
   def testGetDownloadURL(self):