fix compiled app in py3

gluon/compileapp.py

@@ -44,18 +44,15 @@ from functools import reduce
 logger = logging.getLogger("web2py")
 from gluon import rewrite
 from gluon.custom_import import custom_import_install
-
-try:
-    import py_compile
-except:
-    logger.warning('unable to import py_compile')
+import py_compile
 
 is_pypy = settings.global_settings.is_pypy
 is_gae = settings.global_settings.web2py_runtime_gae
 is_jython = settings.global_settings.is_jython
-
 pjoin = os.path.join
 
+marshal_header_size = 8 if PY2 else 12
+
 TEST_CODE = \
     r"""
 def _TEST():
@@ -456,7 +453,8 @@ def save_pyc(filename):
     """
     Bytecode compiles the file `filename`
     """
-    py_compile.compile(filename)
+    cfile = "%sc" % filename
+    py_compile.compile(filename, cfile=cfile)
 
 
 def read_pyc(filename):
@@ -470,7 +468,7 @@ def read_pyc(filename):
     data = read_file(filename, 'rb')
     if not is_gae and data[:4] != imp.get_magic():
         raise SystemError('compiled code is incompatible')
-    return marshal.loads(data[8:])
+    return marshal.loads(data[marshal_header_size:])
 
 
 def compile_views(folder, skip_failed_views=False):