remove unnecessary and ugly exec_ compat hack (#87)

src/attr/_compat.py

@@ -17,9 +17,6 @@ def isclass(klass):
     # TYPE is used in exceptions, repr(int) is different on Python 2 and 3.
     TYPE = "type"
 
-    def exec_(code, locals_, globals_):
-        exec("exec code in locals_, globals_")
-
     def iteritems(d):
         return d.iteritems()
 
@@ -31,9 +28,6 @@ def isclass(klass):
 
     TYPE = "class"
 
-    def exec_(code, locals_, globals_):
-        exec(code, locals_, globals_)
-
     def iteritems(d):
         return d.items()
 

src/attr/_make.py

@@ -4,7 +4,7 @@
 import linecache
 
 from . import _config
-from ._compat import exec_, iteritems, isclass, iterkeys
+from ._compat import iteritems, isclass, iterkeys
 from .exceptions import FrozenInstanceError
 
 # This is used at least twice, so cache it here.
@@ -420,7 +420,7 @@ def _add_init(cls, frozen):
         # Save the lookup overhead in __init__ if we need to circumvent
         # immutability.
         globs["_cached_setattr"] = _obj_setattr
-    exec_(bytecode, globs, locs)
+    eval(bytecode, globs, locs)
     init = locs["__init__"]
 
     # In order of debuggers like PDB being able to step through the code,