Search API returns QueryError when Query contains ','(Comma) or = or ()

Question

Using app engine's search API, I tried to search the queries which contain ,, =, (, etc. It returns the following error:

Failed to parse query "engines (Modular)"
Traceback (most recent call last):
  File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1505, in __call__
  rv = self.router.dispatch(request, response)
File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1253, in default_dispatcher
  return route.handler_adapter(request, response)
File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1077, in __call__
  return handler.dispatch()
File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 547, in dispatch
  return self.handle_exception(e, self.app.debug)
File "/base/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 545, in dispatch
  return method(*args, **kwargs)
File "/base/data/home/apps/s~generatestock/12.362076640167792770/search.py", line 1641, in get
  result = find_search_document(search_item)
File "/base/data/home/apps/s~generatestock/12.362076640167792770/search.py", line 177, in find_search_document
  return search.Index(name=_INDEX_NAME).search(query)
File "/base/python27_runtime/python27_lib/versions/1/google/appengine/api/search/search.py", line 2715, in search
  query = Query(query_string=query)
File "/base/python27_runtime/python27_lib/versions/1/google/appengine/api/search/search.py", line 2286, in __init__
_CheckQuery(self._query_string)
File "/base/python27_runtime/python27_lib/versions/1/google/appengine/api/search/search.py", line 1964, in _CheckQuery
  raise QueryError('Failed to parse query "%s"' % query)

QueryError: Failed to parse query "Engines (Modular)"

Why? Does the search API support these characters?

Answer 1

To parse a phrase, use quotes around the phrase:

query = '"Engines (Modular)"'
search.Index(name=_INDEX_NAME).search(query)

You can simply put quotes around an existing query:

query = '"{0}"'.format(query)
search.Index(name=_INDEX_NAME).search(query)

but you probably have to remove existing quotes in the query to make this work. Google's documentation is silent on how to include quotes in your search queries. So the complete, fail-safe method would be:

query = '"{0}"'.format(query.replace('"', ''))
search.Index(name=_INDEX_NAME).search(query)