core: move importer inline data out to class vars.

mitogen/core.py

@@ -918,9 +918,9 @@ class Importer(object):
 
     :param context: Context to communicate via.
     """
-    def __init__(self, router, context, core_src, whitelist=(), blacklist=()):
+    # The Mitogen package is handled specially, since the child context must
-        self._context = context
+    # construct it manually during startup.
-        self._present = {'mitogen': [
+    MITOGEN_PKG_CONTENT = [
         'compat',
         'debug',
         'doas',
@@ -941,21 +941,28 @@ class Importer(object):
         'su',
         'sudo',
         'utils',
-        ]}
+    ]
-        self._lock = threading.Lock()
+
-        self.whitelist = list(whitelist) or ['']
+    ALWAYS_BLACKLIST = [
-        self.blacklist = list(blacklist) + [
         # 2.x generates needless imports for 'builtins', while 3.x does the
-            # same for '__builtin__'. The correct one is built-in, the other
+        # same for '__builtin__'. The correct one is built-in, the other always
-            # always a negative round-trip.
+        # a negative round-trip.
         'builtins',
         '__builtin__',
-            # org.python.core imported by copy, pickle, xml.sax; breaks Jython,
+        # org.python.core imported by copy, pickle, xml.sax; breaks Jython, but
-            # but very unlikely to trigger a bug report.
+        # very unlikely to trigger a bug report.
         'org',
     ]
+
     if PY3:
-            self.blacklist += ['cStringIO']
+        ALWAYS_BLACKLIST += ['cStringIO']
+
+    def __init__(self, router, context, core_src, whitelist=(), blacklist=()):
+        self._context = context
+        self._present = {'mitogen': self.MITOGEN_PKG_CONTENT}
+        self._lock = threading.Lock()
+        self.whitelist = list(whitelist) or ['']
+        self.blacklist = list(blacklist) + self.ALWAYS_BLACKLIST
 
         # Presence of an entry in this map indicates in-flight GET_MODULE.
         self._callbacks = {}