chore(gae): migrate region tags step 1 - at standard/ndb/overview/main.py (#13079)

* chore(gae): add requirements-test.txt and requirements-test.txt to pass nox tests

* chore(gae): add regions to ndb/overview/main.py

Author: eapl-gemugami

appengine/standard/ndb/overview/main.py

@@ -20,6 +20,7 @@
 For more information, see README.md
 """
 
+# [START gae_ndb_overview]
 # [START all]
 import cgi
 import textwrap
@@ -30,14 +31,17 @@
 import webapp2
 
 
+# [START gae_ndb_overview_greeting]
 # [START greeting]
 class Greeting(ndb.Model):
     """Models an individual Guestbook entry with content and date."""
 
     content = ndb.StringProperty()
     date = ndb.DateTimeProperty(auto_now_add=True)
     # [END greeting]
+    # [END gae_ndb_overview_greeting]
 
+    # [START gae_ndb_overview_query]
     # [START query]
     @classmethod
     def query_book(cls, ancestor_key):
@@ -51,6 +55,7 @@ def get(self):
         ancestor_key = ndb.Key("Book", guestbook_name or "*notitle*")
         greetings = Greeting.query_book(ancestor_key).fetch(20)
         # [END query]
+        # [END gae_ndb_overview_query]
 
         greeting_blockquotes = []
         for greeting in greetings:
@@ -89,6 +94,7 @@ def get(self):
         )
 
 
+# [START gae_ndb_overview_submit]
 # [START submit]
 class SubmitForm(webapp2.RequestHandler):
     def post(self):
@@ -101,8 +107,10 @@ def post(self):
         )
         greeting.put()
         # [END submit]
+        # [END gae_ndb_overview_submit]
         self.redirect("/?" + urllib.urlencode({"guestbook_name": guestbook_name}))
 
 
 app = webapp2.WSGIApplication([("/", MainPage), ("/sign", SubmitForm)])
 # [END all]
+# [END gae_ndb_overview]

appengine/standard/ndb/overview/requirements-test.txt

@@ -0,0 +1,6 @@
+# pin pytest to 4.6.11 for Python2.
+pytest==4.6.11; python_version < '3.0'
+
+# pytest==8.3.4 and six==1.17.0 for Python3.
+pytest==8.3.4; python_version >= '3.0'
+six==1.17.0