simplify reading version

setup.py

@@ -9,26 +9,21 @@
 with open("requirements.in") as f:
     requirements = f.read().splitlines()
 
-# Solution from https://packaging.python.org/guides/single-sourcing-package-version/
-def read(rel_path: str) -> str:
-    """Read file."""
-    here = os.path.abspath(os.path.dirname(__file__))
-    with codecs.open(os.path.join(here, rel_path), "r") as fp:
-        return fp.read()
 
-
-def get_version(rel_path: str) -> str:
+def get_version() -> str:
     """Parse version from file content."""
-    for line in read(rel_path).splitlines():
-        if line.startswith("VERSION"):
-            delim = '"' if '"' in line else "'"
-            return line.split(delim)[1]
+    with open("src/audiobook_tags/version.py") as f:
+        version_lines = f.read().splitlines()
+        for line in version_lines:
+            if line.startswith("VERSION"):
+                delim = '"' if '"' in line else "'"
+                return line.split(delim)[1]
     raise RuntimeError("Unable to find version string.")
 
 
 setuptools.setup(
     name="audiobook-tags",
-    version=get_version("src/audiobook_tags/version.py"),
+    version=get_version(),
     author="Andrey Sorokin",
     author_email="andrey@sorokin.engineer",
     description="Fix mp3 tags to use in iTunes/iPhone audiobooks",