factor out regex pattern

Author: bisgaard-itis

packages/service-library/src/servicelib/utils_meta.py

@@ -7,6 +7,10 @@
 from packaging.version import Version
 from pydantic import TypeAdapter
 
+_APP_NAME_PATTERN = re.compile(
+    r"^[a-z]+(-[a-z]+)*$"
+)  # matches lowercase string with words separated by dashes (no whitespace)
+
 
 class PackageInfo:
     """Thin wrapper around pgk_resources.Distribution to access package distribution metadata
@@ -29,7 +33,7 @@ def __init__(self, package_name: str):
         """
         self._distribution = distribution(package_name)
         # property checks
-        if re.match(r"^[a-z]+(-[a-z]+)*$", self.app_name) is None:
+        if re.match(_APP_NAME_PATTERN, self.app_name) is None:
             raise ValueError(
                 f"Invalid package name {self.app_name}. "
                 "It must be all lowercase and words separated by dashes ('-')."