pkg_resources: Clarify some methods return bytes, not str (#4243)

Author: abravalheri

newsfragments/4243.bugfix.rst

@@ -0,0 +1 @@
+Clarify some `pkg_resources` methods return `bytes`, not `str`. Also return an empty `bytes` in ``EmptyProvider._get`` -- by :user:`Avasam`

pkg_resources/__init__.py

@@ -566,8 +566,8 @@ def get_resource_stream(self, manager, resource_name):
 
         `manager` must be an ``IResourceManager``"""
 
-    def get_resource_string(self, manager, resource_name):
-        """Return a string containing the contents of `resource_name`
+    def get_resource_string(self, manager, resource_name) -> bytes:
+        """Return the contents of `resource_name` as :obj:`bytes`
 
         `manager` must be an ``IResourceManager``"""
 
@@ -1203,8 +1203,8 @@ def resource_stream(self, package_or_requirement, resource_name):
             self, resource_name
         )
 
-    def resource_string(self, package_or_requirement, resource_name):
-        """Return specified resource as a string"""
+    def resource_string(self, package_or_requirement, resource_name) -> bytes:
+        """Return specified resource as :obj:`bytes`"""
         return get_provider(package_or_requirement).get_resource_string(
             self, resource_name
         )
@@ -1480,7 +1480,7 @@ def get_resource_filename(self, manager, resource_name):
     def get_resource_stream(self, manager, resource_name):
         return io.BytesIO(self.get_resource_string(manager, resource_name))
 
-    def get_resource_string(self, manager, resource_name):
+    def get_resource_string(self, manager, resource_name) -> bytes:
         return self._get(self._fn(self.module_path, resource_name))
 
     def has_resource(self, resource_name):
@@ -1650,7 +1650,7 @@ def _validate_resource_path(path):
             DeprecationWarning,
         )
 
-    def _get(self, path):
+    def _get(self, path) -> bytes:
         if hasattr(self.loader, 'get_data'):
             return self.loader.get_data(path)
         raise NotImplementedError(
@@ -1707,7 +1707,7 @@ def _listdir(self, path):
     def get_resource_stream(self, manager, resource_name):
         return open(self._fn(self.module_path, resource_name), 'rb')
 
-    def _get(self, path):
+    def _get(self, path) -> bytes:
         with open(path, 'rb') as stream:
             return stream.read()
 
@@ -1732,8 +1732,8 @@ class EmptyProvider(NullProvider):
 
     _isdir = _has = lambda self, path: False
 
-    def _get(self, path):
-        return ''
+    def _get(self, path) -> bytes:
+        return b''
 
     def _listdir(self, path):
         return []