Re-arrange _first_line_re to put core functionality at the top level

1 files changed, 8 insertions, 4 deletions

diff --git a/setuptools/command/easy_install.py b/setuptools/command/easy_install.py
index 5206698f..de139f2f 100755
--- a/setuptools/command/easy_install.py
+++ b/setuptools/command/easy_install.py
@@ -1530,11 +1530,15 @@ class PthDistributions(Environment):
 
 
 def _first_line_re():
-    # first_line_re in Python >=3.1.4 and >=3.2.1 is a bytes pattern.
-    if not isinstance(first_line_re.pattern, str):
-        return re.compile(first_line_re.pattern.decode())
+    """
+    Return a regular expression based on first_line_re suitable for matching
+    strings.
+    """
+    if isinstance(first_line_re.pattern, str):
+        return first_line_re
 
-    return first_line_re
+    # first_line_re in Python >=3.1.4 and >=3.2.1 is a bytes pattern.
+    return re.compile(first_line_re.pattern.decode())
 
 
 def get_script_header(script_text, executable=sys_executable, wininst=False):