Adding GitImplementation of Ground and tests

python/README.md

@@ -0,0 +1,3 @@
+# Ground Git
+
+This folder contains the git implementation for the Ground API, where are the Ground objects are stored in a git repository named 'ground_git_dir', which is automatically created when you initialize a GitImplementation Object. This directory will persist with multiple executions of a program that uses the GitImplementation Object, given you run the program from the same directory every time. However, in order to use the GitImplementation Object, you must call the .init() method every time before perfoming any operation. The .init() method will automatically check for previous initialization and will call init again which is safe but will not replace the repo and your existing work. The ids will carry on with the highest id and continue, not replacing older files. However, this implementation does not handle the case where the folder has been previously manually created, then initialized to some other repo with previous commits that have no relation to the ground objects, it will just continue to commit to that initial repo.

python/ground/common/model/core/rich_version.py

@@ -1,5 +1,5 @@
 from ground.common.model.version.version import Version
-
+from ground.common.model.version.tag import Tag
 
 class RichVersion(Version):
 
@@ -8,6 +8,10 @@ def __init__(self, json_payload):
 
         self._tags = json_payload.get('tags', {}) or {}
 
+        for key, value in list(self._tags.items()):
+            if not isinstance(value, Tag):
+                self._tags[key] = Tag(value)
+
         svid = json_payload.get('structureVersionId')
         if svid is None or svid <= 0:
             self._structure_version_id = -1