Clean up a couple more references to unicode

IPython/core/magics/basic.py

@@ -27,6 +27,7 b' from IPython.utils.text import format_screen, dedent, indent'
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils.ipstruct import Struct
 from IPython.utils.path import unquote_filename
+from IPython.utils.py3compat import unicode_type
 from IPython.utils.warn import warn, error
 
 #-----------------------------------------------------------------------------
@@ -599,7 +600,7 b' Defaulting color scheme to \'NoColor\'"""'
              'format. The filename argument gives the name of the source file.'
     )
     @magic_arguments.argument(
-        'filename', type=unicode,
+        'filename', type=unicode_type,
         help='Notebook name or filename'
     )
     @line_magic

IPython/core/magics/osm.py

@@ -36,6 +36,7 b' from IPython.testing.skipdoctest import skip_doctest'
 from IPython.utils.openpy import source_to_unicode
 from IPython.utils.path import unquote_filename
 from IPython.utils.process import abbrev_cwd
+from IPython.utils.py3compat import unicode_type
 from IPython.utils.terminal import set_term_title
 
 #-----------------------------------------------------------------------------
@@ -714,7 +715,7 b' class OSMagics(Magics):'
              'The file will be created if it does not exist.'
     )
     @magic_arguments.argument(
-        'filename', type=unicode,
+        'filename', type=unicode_type,
         help='file to write'
     )
     @cell_magic