Use open from io to support encoding parameter in python 2

python/mxnet/base.py

@@ -20,6 +20,7 @@
 """ctypes library of mxnet and helper functions."""
 from __future__ import absolute_import
 
+import io
 import re
 import atexit
 import ctypes
@@ -32,6 +33,7 @@
 from . import libinfo
 
 __all__ = ['MXNetError']
+
 #----------------------------
 # library loading
 #----------------------------
@@ -76,6 +78,26 @@ def data_dir():
     """
     return os.getenv('MXNET_HOME', data_dir_default())
 
+class _Py2CompatibleUnicodeFileWriter(object):
+    """
+    Wraps a file handle decorating the write command to unicode the content before writing.
+    This makes writing files opened with encoding='utf-8' compatible with Python 2
+    """
+
+    def __init__(self, file_handle):
+        self._file_handle = file_handle
+        if sys.version_info[0] > 2:
+            self.unicode = str
+        else:
+            from functools import partial
+            self.unicode = partial(unicode, encoding="utf-8")
+
+    def write(self, value):
+        self._file_handle.write(self.unicode(value))
+
+    def __getattr__(self, name):
+        return getattr(self._file_handle, name)
+
 
 class _NullType(object):
     """Placeholder for arguments"""
@@ -672,7 +694,7 @@ def get_module_file(module_name):
         module_path = module_name.split('.')
         module_path[-1] = 'gen_' + module_path[-1]
         file_name = os.path.join(path, '..', *module_path) + '.py'
-        module_file = open(file_name, 'w', encoding="utf-8")
+        module_file = _Py2CompatibleUnicodeFileWriter(io.open(file_name, 'w', encoding="utf-8"))
         dependencies = {'symbol': ['from ._internal import SymbolBase',
                                    'from ..base import _Null'],
                         'ndarray': ['from ._internal import NDArrayBase',