Python Bindings: Services API, logging & XML enhancements

- Improve logging dump of 'postdata'
- Add an option to return raw XML data, {'rawxml': True}

Some lxml.etree functions, e.g. fromstring()/tostring() cause pylint 'I'
messages. users may want to add the following to their .pylintrc (or just
add # pylint: disable=c-extension-no-member inline):

    [MESSAGE-CONTROL]
    disable=c-extension-no-member

Closes #13619

Signed-off-by: Bill Meek <billmeek@mythtv.org>

mythtv/bindings/python/MythTV/services_api/send.py

@@ -141,6 +141,10 @@ def send(self, endpoint='', postdata=None, rest='', opts=None):
                          its response in XML rather than JSON. Defaults to
                          False.
 
+        opts['rawxml']:  If True, causes the backend to send it's response in
+                         XML as bytes. This can be easily parsed by Python's
+                         'lxml.etree.fromstring()'. Defaults to False.
+
         opts['wrmi']:    If True and there is postdata, the URL is then sent to
                          the server.
 
@@ -296,6 +300,9 @@ def send(self, endpoint='', postdata=None, rest='', opts=None):
         if self.opts['usexml']:
             return response.text
 
+        if self.opts['rawxml']:
+            return response.content
+
         try:
             return response.json()
         except ValueError as err:
@@ -320,7 +327,7 @@ def _set_missing_opts(self):
         if not isinstance(self.opts, dict):
             self.opts = {}
 
-        for option in ('noetag', 'nogzip', 'usexml', 'wrmi', 'wsdl'):
+        for option in ('noetag', 'nogzip', 'usexml', 'rawxml', 'wrmi', 'wsdl'):
             try:
                 self.opts[option]
             except (KeyError, TypeError):
@@ -368,8 +375,8 @@ def _validate_postdata(self):
             raise RuntimeError('usage: postdata must be passed as a dict')
 
         self.logger.debug('The following postdata was included:')
-        for key in self.postdata:
-            self.logger.debug('%15s: %s', key, self.postdata[key])
+        for k, v in self.postdata.items():
+            self.logger.debug('%15s: %s', k, v)
 
         if not self.opts['wrmi']:
             raise RuntimeWarning('wrmi=False')
@@ -396,7 +403,7 @@ def _create_session(self):
         else:
             self.session.headers.update({'Accept-Encoding': 'gzip,deflate'})
 
-        if self.opts['usexml']:
+        if self.opts['usexml'] or self.opts['rawxml']:
             self.session.headers.update({'Accept': ''})
         else:
             self.session.headers.update({'Accept': 'application/json'})