Only catch the errors that can actually occur, as reported in bug #411881.

Lib/types.py

@@ -31,7 +31,8 @@ FunctionType = type(_f)
 LambdaType = type(lambda: None)         # Same as FunctionType
 try:
     CodeType = type(_f.func_code)
-except:
+except RuntimeError:
+    # Execution in restricted environment
     pass
 
 def g():
@@ -54,7 +55,8 @@ ModuleType = type(sys)
 
 try:
     FileType = type(sys.__stdin__)
-except:
+except AttributeError:
+    # Not available in restricted mode
     pass
 XRangeType = type(xrange(0))
 
@@ -65,7 +67,9 @@ except TypeError:
         tb = sys.exc_info()[2]
         TracebackType = type(tb)
         FrameType = type(tb.tb_frame)
-    except:
+    except AttributeError:
+        # In the restricted environment, exc_info returns (None, None,
+        # None) Then, tb.tb_frame gives an attribute error
         pass
     tb = None; del tb
 

Lib/urllib.py

@@ -134,7 +134,7 @@ class URLopener:
             for file in self.__tempfiles:
                 try:
                     self.__unlink(file)
-                except:
+                except OSError:
                     pass
             del self.__tempfiles[:]
         if self.tempcache:
@@ -1069,7 +1069,7 @@ def unquote(s):
             try:
                 myappend(mychr(myatoi(item[:2], 16))
                      + item[2:])
-            except:
+            except ValueError:
                 myappend('%' + item)
         else:
             myappend('%' + item)