print_figure returns unicode for svg

IPython/core/pylabtools.py

@@ -96,7 +96,10 b' def figsize(sizex, sizey):'
 
 
 def print_figure(fig, fmt='png', bbox_inches='tight', **kwargs):
-    """Print a figure to an image, and return the resulting bytes
+    """Print a figure to an image, and return the resulting file data
+    
+    Returned data will be bytes unless ``fmt='svg'``,
+    in which case it will be unicode.
     
     Any keyword args are passed to fig.canvas.print_figure,
     such as ``quality`` or ``bbox_inches``.
@@ -125,7 +128,10 b" def print_figure(fig, fmt='png', bbox_inches='tight', **kwargs):"
     
     bytes_io = BytesIO()
     fig.canvas.print_figure(bytes_io, **kw)
-    return bytes_io.getvalue()
+    data = bytes_io.getvalue()
+    if fmt == 'svg':
+        data = data.decode('utf-8')
+    return data
     
 def retina_figure(fig, **kwargs):
     """format a figure as a pixel-doubled (retina) PNG"""

IPython/core/tests/test_pylabtools.py

@@ -58,7 +58,7 b' def test_figure_to_svg():'
     ax.plot([1,2,3])
     plt.draw()
     svg = pt.print_figure(fig, 'svg')[:100].lower()
-    nt.assert_in(b'doctype svg', svg)
+    nt.assert_in(u'doctype svg', svg)
 
 def _check_pil_jpeg_bytes():
     """Skip if PIL can't write JPEGs to BytesIO objects"""