fix(tgapi): take textgridUri from metadata, not from result element

also, lint some

close #6

src/repdav/tgapi.py

-"""Communication with the different Textgrid APIs.
-"""
+"""Communicate with the different Textgrid APIs."""
 import io
-import logging
-import requests
 import xml.etree.ElementTree as ET
+
+import requests
 #from typing import List
 from zeep import Client
 from zeep.exceptions import TransportError
 
 from .config import TextgridConfig
 
+__docformat__ = 'restructuredtext en'
 DEFAULT_API_VERSION = "1.0"
-_logger = logging.getLogger(__name__)
 
 
 def lookup_api_path(internal_name: str, api_version: str = DEFAULT_API_VERSION) -> str:
@@ -52,7 +51,8 @@ class TextgridAuth:
         self._config = TextgridConfig()
 
     def _connect(self) -> Client:
-        """Internal helper that provides a SOAP client that is configured for the use with the Textgrid Auth service.
+        """Internal helper that provides a SOAP client that is configured for
+        the use with the Textgrid Auth service.
 
         :return: A SOAP client
         :rtype: zeep.Client
@@ -89,9 +89,9 @@ class TextgridSearch:
         :rtype: dict
         """
         uri = self._config.host + DEFAULT_API_VERSION + lookup_api_path("info")
-        r = requests.get(uri + textgrid_uri + "?sid=" + sid)
+        response = requests.get(uri + textgrid_uri + "?sid=" + sid)
         # TODO implement error handling on http status not in 200..299
-        return self._process_response(r)
+        return self._process_response(response)
 
     def get_project_contents(self, sid: str, project_id: str) -> dict:
         """Get objects belonging to a project, filtered by objects that are in
@@ -100,8 +100,9 @@ class TextgridSearch:
         :return: A dictionary with keys of Textgrid URIs and values of metadata dictionaries
         :rtype: dict
         """
-        r = requests.get(self._config.nav_address + project_id + "?sid=" + sid)
-        return self._process_response(r)
+        response = requests.get(
+            self._config.nav_address + project_id + "?sid=" + sid)
+        return self._process_response(response)
 
     def get_aggregation_contents(self, sid: str, textgrid_uri: str) -> dict:
         """Get child resources of an aggregation.
@@ -113,9 +114,9 @@ class TextgridSearch:
         :return: A dictionary with keys of Textgrid URIs and values of metadata dictionaries
         :rtype: dict
         """
-        r = requests.get(self._config.nav_address + "agg/" +
-                         textgrid_uri + "?sid=" + sid)
-        return self._process_response(r)
+        response = requests.get(self._config.nav_address + "agg/" +
+                                textgrid_uri + "?sid=" + sid)
+        return self._process_response(response)
 
     def _process_response(self, response: requests.Response) -> dict:
         """Process the response of a Textgrid Search Service into a dictionary.
@@ -132,7 +133,7 @@ class TextgridSearch:
         tg_results = element_tree.findall("tgs:result", namespaces=namespaces)
         result_dict = {}
         for result in tg_results:
-            result_dict[result.get("textgridUri")] = {
+            result_dict[result.find("./object/generic/generated/textgridUri", namespaces).text] = {
                 # title^=name, format^=content_type, extent^=content_length
                 "title": result.find("./object/generic/provided/title", namespaces).text,
                 "format": result.find("./object/generic/provided/format", namespaces).text,
@@ -141,7 +142,8 @@ class TextgridSearch:
 
         return result_dict
 
-    def _register_namespaces(self, xml: str) -> dict:
+    @staticmethod
+    def _register_namespaces(xml: str) -> dict:
         """Register namespaces to the global ElementTree and return a
         dictionary of them.
 
@@ -155,6 +157,7 @@ class TextgridSearch:
         # create a dictionary containing the namespace prefix and it's uri. The
         # underscore is utilized to remove the "start-ns" output. `iterparse`
         # returns an iterator providing (event, elem) pairs.
+        # see https://medium.datadriveninvestor.com/getting-started-using-pythons-elementtree-to-navigate-xml-files-dc9bc720eaa6
         namespaces = {node[0]: node[1]
                       for _, node in ET.iterparse(xml_stream, events=['start-ns'])}
 
@@ -167,6 +170,7 @@ class TextgridSearch:
 
 class TextgridCRUD:
     """Provide access to the Textgrid CRUD Service."""
+
     def __init__(self):
         self._config = TextgridConfig()
 
@@ -189,7 +193,8 @@ class TextgridCRUD:
         return self._process_response(response)
 
     def _get_resource(self, sid: str, textgrid_uri: str) -> requests.Response:
-        """Helper function to get the response headers of a requested resource and defer the download of the message body.
+        """Helper function to get the response headers of a requested resource
+        and defer the download of the message body.
 
         :param sid: Session ID
         :type sid: str
@@ -200,12 +205,13 @@ class TextgridCRUD:
         """
         uri = self._config.host + DEFAULT_API_VERSION + lookup_api_path("crud")
         # defer downloading the response body until accessing Response.content
-        r = requests.get(uri + textgrid_uri +
-                         "/data?sessionId=" + sid, stream=True)
+        response = requests.get(uri + textgrid_uri +
+                                "/data?sessionId=" + sid, stream=True)
         # TODO implement error handling on http status not in 200..299
-        return r
+        return response
 
-    def _process_response(self, response: requests.Response) -> dict:
+    @staticmethod
+    def _process_response(response: requests.Response) -> dict:
         # only called by `get_metadata` => currently unused
         result_dict = {}
         result_dict["content-type"] = response.headers.get("content-type")