Use python 3 engine

plugin/snake.vim

@@ -1,4 +1,4 @@
-python << EOF
+python3 << EOF
 import sys
 import vim
 sys.path.insert(0, vim.eval("expand('<sfile>:p:h')"))

plugin/snake/__init__.py

@@ -150,7 +150,7 @@ def abbrev(word, expansion, local=False):
 
     if callable(expansion):
         fn_str = register_fn(expansion)
-        expansion = "<C-r>=pyeval('%s')<CR>" % escape_string_sq(fn_str)
+        expansion = "<C-r>=py3eval('%s')<CR>" % escape_string_sq(fn_str)
 
     command("%s %s %s" % (cmd, word, expansion))
 
@@ -239,7 +239,7 @@ def multi_let(namespace, **name_values):
         let(name, value, namespace=namespace)
 
 def _serialize_obj(obj):
-    if isinstance(obj, basestring):
+    if isinstance(obj, str):
         obj = "'%s'" % escape_string_sq(obj)
     # TODO allow other kinds of serializations?
     return obj
@@ -405,7 +405,7 @@ def wrapped():
             fn = wrapped
 
         call = register_fn(fn)
-        command("%s <silent> %s :python %s<CR>" % (map_command, key, call))
+        command("%s <silent> %s :python3 %s<CR>" % (map_command, key, call))
 
     else:
         command("%s %s %s" % (map_command, key, maybe_fn))
@@ -647,7 +647,7 @@ def wrapped(fn):
         command("autocmd!")
         ctx = AutoCommandContext()
         call = register_fn(partial(fn, ctx))
-        command("autocmd %s %s :python %s" % (event, filetype, call))
+        command("autocmd %s %s :python3 %s" % (event, filetype, call))
         command("augroup END")
         return fn
 
@@ -661,4 +661,4 @@ def wrapped(fn):
 if "snake.plugin_loader" in sys.modules:
     plugin_loader = reload(plugin_loader)
 else:
-    import plugin_loader
+    from . import plugin_loader