Use a stricter regex for matching the Python version

Co-authored-by: Kevin Puetz <[email protected]>

Author: pradyunsg

tests/lib/test_lib.py

@@ -45,7 +45,7 @@ def test_correct_pip_version(script):
     # distribution
     pip_folder_outputed = re.match(
         r"pip \d+(\.[\d]+)+(\.?(b|rc|dev|pre|post)\d+)? from (.*) "
-        r"\(python \d(.[\d]+)+\)$",
+        r"\(python \d+(\.[\d]+)+\)$",
         result.stdout,
     ).group(4)
     pip_folder = join(SRC_DIR, "src", "pip")