Fix artist.get_bio_content() to return None if bio is empty

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/asottile/pyupgrade
-    rev: v2.1.0
+    rev: v2.4.1
     hooks:
       - id: pyupgrade
         args: ["--py3-plus"]
@@ -15,13 +15,13 @@ repos:
         types: []
 
   - repo: https://gitlab.com/pycqa/flake8
-    rev: 3.7.9
+    rev: 3.8.0a2
     hooks:
       - id: flake8
         additional_dependencies: [flake8-2020, flake8-implicit-str-concat]
 
   - repo: https://github.com/asottile/seed-isort-config
-    rev: v2.1.0
+    rev: v2.1.1
     hooks:
       - id: seed-isort-config
 

RELEASING.md

@@ -4,7 +4,8 @@
       [Travis CI](https://travis-ci.org/pylast/pylast) should be running cleanly for
       all merges to master.
 
-* [ ] Edit release draft, adjust text if needed: https://github.com/pylast/pylast/releases
+* [ ] Edit release draft, adjust text if needed:
+      https://github.com/pylast/pylast/releases
 
 * [ ] Check next tag is correct, amend if needed
 

src/pylast/__init__.py

@@ -1142,7 +1142,12 @@ def __hash__(self):
     def _extract_cdata_from_request(self, method_name, tag_name, params):
         doc = self._request(method_name, True, params)
 
-        return doc.getElementsByTagName(tag_name)[0].firstChild.wholeText.strip()
+        first_child = doc.getElementsByTagName(tag_name)[0].firstChild
+
+        if first_child is None:
+            return None
+
+        return first_child.wholeText.strip()
 
     def _get_things(self, method, thing, thing_type, params=None, cacheable=True):
         """Returns a list of the most played thing_types by this thing."""

tests/test_artist.py

@@ -52,6 +52,17 @@ def test_bio_content(self):
         self.assertIsNotNone(bio)
         self.assertGreaterEqual(len(bio), 1)
 
+    def test_bio_content_none(self):
+        # Arrange
+        # An artist with no biography, with "<content/>" in the API XML
+        artist = pylast.Artist("Mr Sizef + Unquote", self.network)
+
+        # Act
+        bio = artist.get_bio_content()
+
+        # Assert
+        self.assertIsNone(bio)
+
     def test_bio_summary(self):
         # Arrange
         artist = pylast.Artist("Test Artist", self.network)