indexes section in the HTML repr (#7185)

* borrow `Index._repr_inline_` and `inline_index_repr` from a different PR

* implement a crude HTML repr for indexes

* css fixes and tweaks

* escape inline repr

* show one section item per unique index

Show the names of all corresponding coordinates in the same
item (separated by line return).

* also add the indexes section to the DataArray html repr

* make the grouper a bit easier to understand

* add documentation for the display_expand_indexes option

* collapse the indexes section by default

* update the HTML formatting tests

* Update xarray/core/options.py

Co-authored-by: Benoit Bovy <[email protected]>

* whats-new.rst

* improve the index preview contrast

* add the repr_inline PR to the changelog [skip-ci]

Co-authored-by: Benoit Bovy <[email protected]>
Co-authored-by: Benoit Bovy <[email protected]>

Author: keewis

doc/whats-new.rst

@@ -25,6 +25,9 @@ New Features
 
 - Add static typing to plot accessors (:issue:`6949`, :pull:`7052`).
   By `Michael Niklas <https://github.com/headtr1ck>`_.
+- Display the indexes in a new section of the text and HTML reprs
+  (:pull:`6795`, :pull:`7183`, :pull:`7185`)
+  By `Justus Magin <https://github.com/keewis>`_ and `Benoît Bovy <https://github.com/benbovy>`_.
 
 Breaking changes
 ~~~~~~~~~~~~~~~~

xarray/core/formatting_html.py

@@ -6,7 +6,7 @@
 from html import escape
 from importlib.resources import read_binary
 
-from .formatting import inline_variable_array_repr, short_data_repr
+from .formatting import inline_index_repr, inline_variable_array_repr, short_data_repr
 from .options import _get_boolean_with_default
 
 STATIC_FILES = (
@@ -125,6 +125,40 @@ def summarize_vars(variables):
     return f"<ul class='xr-var-list'>{vars_li}</ul>"
 
 
+def short_index_repr_html(index):
+    if hasattr(index, "_repr_html_"):
+        return index._repr_html_()
+
+    return f"<pre>{escape(repr(index))}</pre>"
+
+
+def summarize_index(coord_names, index):
+    name = "<br>".join([escape(str(n)) for n in coord_names])
+
+    index_id = f"index-{uuid.uuid4()}"
+    preview = escape(inline_index_repr(index))
+    details = short_index_repr_html(index)
+
+    data_icon = _icon("icon-database")
+
+    return (
+        f"<div class='xr-index-name'><div>{name}</div></div>"
+        f"<div class='xr-index-preview'>{preview}</div>"
+        f"<div></div>"
+        f"<input id='{index_id}' class='xr-index-data-in' type='checkbox'/>"
+        f"<label for='{index_id}' title='Show/Hide index repr'>{data_icon}</label>"
+        f"<div class='xr-index-data'>{details}</div>"
+    )
+
+
+def summarize_indexes(indexes):
+    indexes_li = "".join(
+        f"<li class='xr-var-item'>{summarize_index(v, i)}</li>"
+        for v, i in indexes.items()
+    )
+    return f"<ul class='xr-var-list'>{indexes_li}</ul>"
+
+
 def collapsible_section(
     name, inline_details="", details="", n_items=None, enabled=True, collapsed=False
 ):
@@ -213,6 +247,13 @@ def array_section(obj):
     expand_option_name="display_expand_data_vars",
 )
 
+index_section = partial(
+    _mapping_section,
+    name="Indexes",
+    details_func=summarize_indexes,
+    max_items_collapse=0,
+    expand_option_name="display_expand_indexes",
+)
 
 attr_section = partial(
     _mapping_section,
@@ -223,6 +264,12 @@ def array_section(obj):
 )
 
 
+def _get_indexes_dict(indexes):
+    return {
+        tuple(index_vars.keys()): idx for idx, index_vars in indexes.group_by_index()
+    }
+
+
 def _obj_repr(obj, header_components, sections):
     """Return HTML repr of an xarray object.
 
@@ -266,6 +313,10 @@ def array_repr(arr):
     if hasattr(arr, "coords"):
         sections.append(coord_section(arr.coords))
 
+    if hasattr(arr, "xindexes"):
+        indexes = _get_indexes_dict(arr.xindexes)
+        sections.append(index_section(indexes))
+
     sections.append(attr_section(arr.attrs))
 
     return _obj_repr(arr, header_components, sections)
@@ -280,6 +331,7 @@ def dataset_repr(ds):
         dim_section(ds),
         coord_section(ds.coords),
         datavar_section(ds.data_vars),
+        index_section(_get_indexes_dict(ds.xindexes)),
         attr_section(ds.attrs),
     ]
 

xarray/core/options.py

@@ -169,34 +169,41 @@ class set_options:
         Colormap to use for nondivergent data plots. If string, must be
         matplotlib built-in colormap. Can also be a Colormap object
         (e.g. mpl.cm.magma)
-    display_expand_attrs : {"default", True, False}:
+    display_expand_attrs : {"default", True, False}
         Whether to expand the attributes section for display of
         ``DataArray`` or ``Dataset`` objects. Can be
 
         * ``True`` : to always expand attrs
         * ``False`` : to always collapse attrs
         * ``default`` : to expand unless over a pre-defined limit
-    display_expand_coords : {"default", True, False}:
+    display_expand_coords : {"default", True, False}
         Whether to expand the coordinates section for display of
         ``DataArray`` or ``Dataset`` objects. Can be
 
         * ``True`` : to always expand coordinates
         * ``False`` : to always collapse coordinates
         * ``default`` : to expand unless over a pre-defined limit
-    display_expand_data : {"default", True, False}:
+    display_expand_data : {"default", True, False}
         Whether to expand the data section for display of ``DataArray``
         objects. Can be
 
         * ``True`` : to always expand data
         * ``False`` : to always collapse data
         * ``default`` : to expand unless over a pre-defined limit
-    display_expand_data_vars : {"default", True, False}:
+    display_expand_data_vars : {"default", True, False}
         Whether to expand the data variables section for display of
         ``Dataset`` objects. Can be
 
         * ``True`` : to always expand data variables
         * ``False`` : to always collapse data variables
         * ``default`` : to expand unless over a pre-defined limit
+    display_expand_indexes : {"default", True, False}
+        Whether to expand the indexes section for display of
+        ``DataArray`` or ``Dataset``. Can be
+
+        * ``True`` : to always expand indexes
+        * ``False`` : to always collapse indexes
+        * ``default`` : to expand unless over a pre-defined limit (always collapse for html style)
     display_max_rows : int, default: 12
         Maximum display rows.
     display_values_threshold : int, default: 200

xarray/static/css/style.css

@@ -244,6 +244,11 @@ body.vscode-dark {
   grid-column: 4;
 }
 
+.xr-index-preview {
+  grid-column: 2 / 5;
+  color: var(--xr-font-color2);
+}
+
 .xr-var-name,
 .xr-var-dims,
 .xr-var-dtype,
@@ -265,14 +270,16 @@ body.vscode-dark {
 }
 
 .xr-var-attrs,
-.xr-var-data {
+.xr-var-data,
+.xr-index-data {
   display: none;
   background-color: var(--xr-background-color) !important;
   padding-bottom: 5px !important;
 }
 
 .xr-var-attrs-in:checked ~ .xr-var-attrs,
-.xr-var-data-in:checked ~ .xr-var-data {
+.xr-var-data-in:checked ~ .xr-var-data,
+.xr-index-data-in:checked ~ .xr-index-data {
   display: block;
 }
 
@@ -282,13 +289,16 @@ body.vscode-dark {
 
 .xr-var-name span,
 .xr-var-data,
+.xr-index-name div,
+.xr-index-data,
 .xr-attrs {
   padding-left: 25px !important;
 }
 
 .xr-attrs,
 .xr-var-attrs,
-.xr-var-data {
+.xr-var-data,
+.xr-index-data {
   grid-column: 1 / -1;
 }
 
@@ -326,7 +336,8 @@ dl.xr-attrs {
 }
 
 .xr-icon-database,
-.xr-icon-file-text2 {
+.xr-icon-file-text2,
+.xr-no-icon {
   display: inline-block;
   vertical-align: middle;
   width: 1em;

xarray/tests/test_formatting_html.py

@@ -102,20 +102,20 @@ def test_repr_of_dataarray(dataarray) -> None:
     assert "dim_0" in formatted
     # has an expanded data section
     assert formatted.count("class='xr-array-in' type='checkbox' checked>") == 1
-    # coords and attrs don't have an items so they'll be be disabled and collapsed
+    # coords, indexes and attrs don't have an items so they'll be be disabled and collapsed
     assert (
-        formatted.count("class='xr-section-summary-in' type='checkbox' disabled >") == 2
+        formatted.count("class='xr-section-summary-in' type='checkbox' disabled >") == 3
     )
 
     with xr.set_options(display_expand_data=False):
         formatted = fh.array_repr(dataarray)
         assert "dim_0" in formatted
-        # has an expanded data section
+        # has a collapsed data section
         assert formatted.count("class='xr-array-in' type='checkbox' checked>") == 0
-        # coords and attrs don't have an items so they'll be be disabled and collapsed
+        # coords, indexes and attrs don't have an items so they'll be be disabled and collapsed
         assert (
             formatted.count("class='xr-section-summary-in' type='checkbox' disabled >")
-            == 2
+            == 3
         )
 
 
@@ -130,19 +130,22 @@ def test_repr_of_dataset(dataset) -> None:
     assert (
         formatted.count("class='xr-section-summary-in' type='checkbox'  checked>") == 3
     )
+    # indexes is collapsed
+    assert formatted.count("class='xr-section-summary-in' type='checkbox'  >") == 1
     assert "<U4" in formatted or ">U4" in formatted
     assert "<IA>" in formatted
 
     with xr.set_options(
         display_expand_coords=False,
         display_expand_data_vars=False,
         display_expand_attrs=False,
+        display_expand_indexes=True,
     ):
         formatted = fh.dataset_repr(dataset)
-        # coords, attrs, and data_vars are collapsed
+        # coords, attrs, and data_vars are collapsed, indexes is expanded
         assert (
             formatted.count("class='xr-section-summary-in' type='checkbox'  checked>")
-            == 0
+            == 1
         )
         assert "<U4" in formatted or ">U4" in formatted
         assert "<IA>" in formatted