REF: register custom DisplayFormatter for table schema (#16198)

* register custom DisplayFormatter for table schema instead of using `_ipython_display_` for custom mime-types * remove unused UnserializableWarning * PEP8 fixes

Author: minrk

pandas/core/config_init.py

@@ -9,6 +9,7 @@
 module is imported, register them here rather then in the module.
 
 """
+import sys
 import warnings
 
 import pandas.core.config as cf
@@ -341,18 +342,36 @@ def mpl_style_cb(key):
 
 
 def table_schema_cb(key):
- # Having _ipython_display_ defined messes with the return value
- # from cells, so the Out[x] dictionary breaks.
- # Currently table schema is the only thing using it, so we'll
- # monkey patch `_ipython_display_` onto NDFrame when config option
- # is set
- # see https://github.com/pandas-dev/pandas/issues/16168
- from pandas.core.generic import NDFrame, _ipython_display_
+ # first, check if we are in IPython
+ if 'IPython' not in sys.modules:
+ # definitely not in IPython
+ return
+ from IPython import get_ipython
+ ip = get_ipython()
+ if ip is None:
+ # still not in IPython
+ return
+
+ formatters = ip.display_formatter.formatters
+
+ mimetype = "application/vnd.dataresource+json"
 
  if cf.get_option(key):
- NDFrame._ipython_display_ = _ipython_display_
- elif getattr(NDFrame, '_ipython_display_', None):
- del NDFrame._ipython_display_
+ if mimetype not in formatters:
+ # define tableschema formatter
+ from IPython.core.formatters import BaseFormatter
+
+ class TableSchemaFormatter(BaseFormatter):
+ print_method = '_repr_table_schema_'
+ _return_type = (dict,)
+ # register it:
+ formatters[mimetype] = TableSchemaFormatter()
+ # enable it if it's been disabled:
+ formatters[mimetype].enabled = True
+ else:
+ # unregister tableschema mime-type
+ if mimetype in formatters:
+ formatters[mimetype].enabled = False
 
 
 with cf.config_prefix('display'):

pandas/core/generic.py

@@ -43,7 +43,6 @@
 import pandas.core.algorithms as algos
 import pandas.core.common as com
 import pandas.core.missing as missing
-from pandas.errors import UnserializableWarning
 from pandas.io.formats.printing import pprint_thing
 from pandas.io.formats.format import format_percentiles
 from pandas.tseries.frequencies import to_offset
@@ -6279,38 +6278,6 @@ def logical_func(self, axis=None, bool_only=None, skipna=None, level=None,
  return set_function_name(logical_func, name, cls)
 
 
-def _ipython_display_(self):
- # Having _ipython_display_ defined messes with the return value
- # from cells, so the Out[x] dictionary breaks.
- # Currently table schema is the only thing using it, so we'll
- # monkey patch `_ipython_display_` onto NDFrame when config option
- # is set
- # see https://github.com/pandas-dev/pandas/issues/16168
- try:
- from IPython.display import display
- except ImportError:
- return None
-
- # Series doesn't define _repr_html_ or _repr_latex_
- latex = self._repr_latex_() if hasattr(self, '_repr_latex_') else None
- html = self._repr_html_() if hasattr(self, '_repr_html_') else None
- try:
- table_schema = self._repr_table_schema_()
- except Exception as e:
- warnings.warn("Cannot create table schema representation. "
- "{}".format(e), UnserializableWarning)
- table_schema = None
- # We need the inital newline since we aren't going through the
- # usual __repr__. See
- # https://github.com/pandas-dev/pandas/pull/14904#issuecomment-277829277
- text = "\n" + repr(self)
-
- reprs = {"text/plain": text, "text/html": html, "text/latex": latex,
- "application/vnd.dataresource+json": table_schema}
- reprs = {k: v for k, v in reprs.items() if v}
- display(reprs, raw=True)
-
-
 # install the indexes
 for _name, _indexer in indexing.get_indexers_list():
  NDFrame._create_indexer(_name, _indexer)

pandas/errors/__init__.py

@@ -57,9 +57,3 @@ class ParserWarning(Warning):
  """
 
 
-class UnserializableWarning(Warning):
- """
- Warning that is raised when a DataFrame cannot be serialized.
-
- .. versionadded:: 0.20.0
- """

pandas/tests/io/formats/test_printing.py

@@ -5,7 +5,6 @@
 import pandas as pd
 
 from pandas import compat
-from pandas.errors import UnserializableWarning
 import pandas.io.formats.printing as printing
 import pandas.io.formats.format as fmt
 import pandas.util.testing as tm
@@ -137,57 +136,46 @@ def setUpClass(cls):
  except ImportError:
  pytest.skip("Mock is not installed")
  cls.mock = mock
+ from IPython.core.interactiveshell import InteractiveShell
+ cls.display_formatter = InteractiveShell.instance().display_formatter
 
  def test_publishes(self):
+
  df = pd.DataFrame({"A": [1, 2]})
  objects = [df['A'], df, df] # dataframe / series
  expected_keys = [
  {'text/plain', 'application/vnd.dataresource+json'},
  {'text/plain', 'text/html', 'application/vnd.dataresource+json'},
  ]
 
- make_patch = self.mock.patch('IPython.display.display')
  opt = pd.option_context('display.html.table_schema', True)
  for obj, expected in zip(objects, expected_keys):
- with opt, make_patch as mock_display:
- handle = obj._ipython_display_()
- assert mock_display.call_count == 1
- assert handle is None
- args, kwargs = mock_display.call_args
- arg, = args # just one argument
-
- assert kwargs == {"raw": True}
- assert set(arg.keys()) == expected
+ with opt:
+ formatted = self.display_formatter.format(obj)
+ assert set(formatted[0].keys()) == expected
 
  with_latex = pd.option_context('display.latex.repr', True)
 
- with opt, with_latex, make_patch as mock_display:
- handle = obj._ipython_display_()
- args, kwargs = mock_display.call_args
- arg, = args
+ with opt, with_latex:
+ formatted = self.display_formatter.format(obj)
 
  expected = {'text/plain', 'text/html', 'text/latex',
  'application/vnd.dataresource+json'}
- assert set(arg.keys()) == expected
+ assert set(formatted[0].keys()) == expected
 
  def test_publishes_not_implemented(self):
  # column MultiIndex
  # GH 15996
  midx = pd.MultiIndex.from_product([['A', 'B'], ['a', 'b', 'c']])
  df = pd.DataFrame(np.random.randn(5, len(midx)), columns=midx)
 
- make_patch = self.mock.patch('IPython.display.display')
  opt = pd.option_context('display.html.table_schema', True)
- with opt, make_patch as mock_display:
- with pytest.warns(UnserializableWarning) as record:
- df._ipython_display_()
- args, _ = mock_display.call_args
- arg, = args # just one argument
+
+ with opt:
+ formatted = self.display_formatter.format(df)
 
  expected = {'text/plain', 'text/html'}
- assert set(arg.keys()) == expected
- assert "orient='table' is not supported for MultiIndex" in (
- record[-1].message.args[0])
+ assert set(formatted[0].keys()) == expected
 
  def test_config_on(self):
  df = pd.DataFrame({"A": [1, 2]})
@@ -209,26 +197,23 @@ def test_config_monkeypatches(self):
  assert not hasattr(df, '_ipython_display_')
  assert not hasattr(df['A'], '_ipython_display_')
 
+ formatters = self.display_formatter.formatters
+ mimetype = 'application/vnd.dataresource+json'
+
  with pd.option_context('display.html.table_schema', True):
- assert hasattr(df, '_ipython_display_')
- # smoke test that it works
- df._ipython_display_()
- assert hasattr(df['A'], '_ipython_display_')
- df['A']._ipython_display_()
+ assert 'application/vnd.dataresource+json' in formatters
+ assert formatters[mimetype].enabled
 
- assert not hasattr(df, '_ipython_display_')
- assert not hasattr(df['A'], '_ipython_display_')
- # re-unsetting is OK
- assert not hasattr(df, '_ipython_display_')
- assert not hasattr(df['A'], '_ipython_display_')
+ # still there, just disabled
+ assert 'application/vnd.dataresource+json' in formatters
+ assert not formatters[mimetype].enabled
 
  # able to re-set
  with pd.option_context('display.html.table_schema', True):
- assert hasattr(df, '_ipython_display_')
+ assert 'application/vnd.dataresource+json' in formatters
+ assert formatters[mimetype].enabled
  # smoke test that it works
- df._ipython_display_()
- assert hasattr(df['A'], '_ipython_display_')
- df['A']._ipython_display_()
+ self.display_formatter.format(cf)
 
 
 # TODO: fix this broken test