Fix style in Colab (#200)

* Generate the target HTML directly
* Test both the connected and offline mode in tests

Author: mwouts

docs/changelog.md

@@ -1,6 +1,13 @@
 ITables ChangeLog
 =================
 
+1.6.1 (2023-10-01)
+------------------
+
+**Fixed**
+- We have fixed an issue when rendering Pandas style objects in Google Colab ([#199](https://github.com/mwouts/itables/issues/199))
+
+
 1.6.0 (2023-09-30)
 ------------------
 

itables/javascript.py

@@ -30,6 +30,7 @@
 logger = logging.getLogger(__name__)
 
 _OPTIONS_NOT_AVAILABLE_WITH_TO_HTML = {
+    "tags",
     "footer",
     "column_filters",
     "maxBytes",
@@ -226,7 +227,15 @@ def replace_value(template, pattern, value):
     after making sure that the pattern is found exactly once."""
     if sys.version_info >= (3,):
         assert isinstance(template, str)
-    assert template.count(pattern) == 1
+    count = template.count(pattern)
+    if not count:
+        raise ValueError("pattern={} was not found in template".format(pattern))
+    elif count > 1:
+        raise ValueError(
+            "pattern={} was found multiple times ({}) in template".format(
+                pattern, count
+            )
+        )
     return template.replace(pattern, value)
 
 
@@ -410,12 +419,6 @@ def to_html_datatable_using_to_html(
     # These options are used here, not in DataTable
     classes = kwargs.pop("classes")
     style = kwargs.pop("style")
-    tags = kwargs.pop("tags")
-
-    if caption is not None:
-        tags = '{}<caption style="white-space: nowrap; overflow: hidden">{}</caption>'.format(
-            tags, caption
-        )
 
     showIndex = kwargs.pop("showIndex")
 
@@ -434,36 +437,51 @@ def to_html_datatable_using_to_html(
             # Polars DataFrame
             showIndex = False
 
-    if not showIndex:
-        try:
-            df.hide()
-        except AttributeError:
-            # Not a Pandas Styler object
-            pass
-
     if "dom" not in kwargs and _df_fits_in_one_page(df, kwargs):
         kwargs["dom"] = "t"
 
-    tableId = tableId or str(uuid.uuid4())
+    tableId = (
+        tableId
+        # default UUID in Pandas styler objects has uuid_len=5
+        or str(uuid.uuid4())[:5]
+    )
     if isinstance(df, pd_style.Styler):
-        df.set_uuid(tableId)
-        tableId = "T_" + tableId
-        table_html = df.to_html()
-    else:
-        table_html = df.to_html(table_id=tableId)
+        if not showIndex:
+            try:
+                df = df.hide()
+            except AttributeError:
+                pass
 
-    if style:
-        style = 'style="{}"'.format(style)
-    else:
-        style = ""
+        if style:
+            style = 'style="{}"'.format(style)
+        else:
+            style = ""
 
-    html_table = replace_value(
-        table_html,
-        '<table id="{}">'.format(tableId),
-        """<table id="{tableId}" class="{classes}"{style}>{tags}""".format(
-            tableId=tableId, classes=classes, style=style, tags=tags
-        ),
-    )
+        try:
+            to_html_args = dict(
+                table_uuid=tableId,
+                table_attributes="""class="{classes}"{style}""".format(
+                    classes=classes, style=style
+                ),
+                caption=caption,
+            )
+            html_table = df.to_html(**to_html_args)
+        except TypeError:
+            if caption is not None:
+                warnings.warn(
+                    "caption is not supported by Styler.to_html in your version of Pandas"
+                )
+            del to_html_args["caption"]
+            html_table = df.to_html(**to_html_args)
+        tableId = "T_" + tableId
+    else:
+        if caption is not None:
+            raise NotImplementedError(
+                "caption is not supported when using df.to_html. "
+                "Use either Pandas Style, or set use_to_html=False."
+            )
+        # NB: style is not available neither
+        html_table = df.to_html(table_id=tableId, classes=classes)
 
     return html_table_from_template(
         html_table,
@@ -606,5 +624,6 @@ def safe_reset_index(df):
 
 def show(df=None, caption=None, **kwargs):
     """Show a dataframe"""
-    html = to_html_datatable(df, caption=caption, connected=_CONNECTED, **kwargs)
+    connected = kwargs.pop("connected", _CONNECTED)
+    html = to_html_datatable(df, caption=caption, connected=connected, **kwargs)
     display(HTML(html))

itables/version.py

@@ -1,3 +1,3 @@
 """ITables' version number"""
 
-__version__ = "1.6.0"
+__version__ = "1.6.1"

tests/conftest.py

@@ -1,7 +1,7 @@
 import pandas as pd
 import pytest
 
-from itables.sample_dfs import get_dict_of_test_dfs
+from itables.sample_dfs import PANDAS_VERSION_MAJOR, get_dict_of_test_dfs
 
 
 @pytest.fixture(params=list(get_dict_of_test_dfs()))
@@ -19,3 +19,13 @@ def lengthMenu(request):
     if request.param == "2D-array":
         return [[10, 25, 50, 100, -1], [10, 25, 50, 100, "All"]]
     return None
+
+
+@pytest.fixture(params=[False, True])
+def connected(request):
+    return request.param
+
+
+@pytest.fixture(params=[False, True] if PANDAS_VERSION_MAJOR >= 1 else [False])
+def use_to_html(request):
+    return request.param

tests/test_javascript.py

@@ -1,4 +1,26 @@
-from itables.javascript import _df_fits_in_one_page, to_html_datatable
+import pytest
+
+from itables.javascript import _df_fits_in_one_page, replace_value, to_html_datatable
+
+
+def test_replace_value(
+    template="line1\nline2\nline3\n", pattern="line2", value="new line2"
+):
+    assert replace_value(template, pattern, value) == "line1\nnew line2\nline3\n"
+
+
+def test_replace_value_not_found(
+    template="line1\nline2\nline3\n", pattern="line4", value="new line4"
+):
+    with pytest.raises(ValueError, match="not found"):
+        assert replace_value(template, pattern, value)
+
+
+def test_replace_value_multiple(
+    template="line1\nline2\nline2\n", pattern="line2", value="new line2"
+):
+    with pytest.raises(ValueError, match="found multiple times"):
+        assert replace_value(template, pattern, value)
 
 
 def test_warn_on_unexpected_types_not_in_html(df):

tests/test_json_dumps.py

@@ -27,19 +27,19 @@ def coloredColumnDefs():
     ]
 
 
-def test_warning_when_eval_functions_is_missing(df, coloredColumnDefs):
+def test_warning_when_eval_functions_is_missing(df, coloredColumnDefs, connected):
     with pytest.warns(UserWarning, match="starts with 'function'"):
-        show(df, columnDefs=coloredColumnDefs)
+        show(df, connected=connected, columnDefs=coloredColumnDefs)
 
 
-def test_no_warning_when_eval_functions_is_false(df, coloredColumnDefs):
+def test_no_warning_when_eval_functions_is_false(df, coloredColumnDefs, connected):
     warnings.simplefilter("error")
-    show(df, columnDefs=coloredColumnDefs, eval_functions=False)
+    show(df, connected=connected, columnDefs=coloredColumnDefs, eval_functions=False)
 
 
-def test_no_warning_when_eval_functions_is_true(df, coloredColumnDefs):
+def test_no_warning_when_eval_functions_is_true(df, coloredColumnDefs, connected):
     warnings.simplefilter("error")
-    show(df, columnDefs=coloredColumnDefs, eval_functions=True)
+    show(df, connected=connected, columnDefs=coloredColumnDefs, eval_functions=True)
 
 
 @pytest.mark.parametrize("obj", ["a", 1, 1.0, [1.0, "a", {"a": [0, 1]}]])

tests/test_polars.py

@@ -12,12 +12,12 @@
 @pytest.mark.parametrize(
     "name,x", [(name, x) for name, x in get_dict_of_test_series(polars=True).items()]
 )
-def test_show_polars_series(name, x):
-    to_html_datatable(x)
+def test_show_polars_series(name, x, use_to_html):
+    to_html_datatable(x, use_to_html)
 
 
 @pytest.mark.parametrize(
     "name,df", [(name, df) for name, df in get_dict_of_test_dfs(polars=True).items()]
 )
-def test_show_polars_df(name, df):
-    to_html_datatable(df)
+def test_show_polars_df(name, df, use_to_html):
+    to_html_datatable(df, use_to_html)

tests/test_sample_dfs.py

@@ -32,51 +32,61 @@
     pytestmark.append(pytest.mark.filterwarnings("ignore::DeprecationWarning"))
 
 
-def test_get_countries():
+def test_get_countries(connected, use_to_html):
     df = get_countries()
     assert len(df.columns) > 5
     assert len(df.index) > 100
-    show(df)
+    show(df, connected=connected, use_to_html=use_to_html)
 
 
 @pytest.mark.skipif(sys.version_info < (3,), reason="fails in Py2")
-def test_get_population():
+def test_get_population(connected, use_to_html):
     x = get_population()
     assert len(x) > 30
     assert x.max() > 7e9
-    show(x)
+    show(x, connected=connected, use_to_html=use_to_html)
 
 
-def test_get_indicators():
+def test_get_indicators(connected, use_to_html):
     df = get_indicators()
     assert len(df.index) == 500
     assert len(df.columns)
-    show(df)
+    show(df, connected=connected, use_to_html=use_to_html)
 
 
 @pytest.mark.skipif(
     sys.version_info < (3, 7),
     reason="AttributeError: 'Styler' object has no attribute 'to_html'",
 )
-def test_get_pandas_styler():
+def test_get_pandas_styler(connected, use_to_html):
     styler = get_pandas_styler()
-    show(styler)
+    show(styler, connected=connected, use_to_html=use_to_html)
 
 
 def kwargs_remove_none(**kwargs):
     return {key: value for key, value in kwargs.items() if value is not None}
 
 
-def test_show_test_dfs(df, lengthMenu, monkeypatch):
+def test_show_test_dfs(df, connected, use_to_html, lengthMenu, monkeypatch):
     if "bigint" in df.columns:
         monkeypatch.setattr("itables.options.warn_on_int_to_str_conversion", False)
-    show(df, **kwargs_remove_none(lengthMenu=lengthMenu))
+    show(
+        df,
+        connected=connected,
+        use_to_html=use_to_html,
+        **kwargs_remove_none(lengthMenu=lengthMenu)
+    )
 
 
-def test_to_html_datatable(df, lengthMenu, monkeypatch):
+def test_to_html_datatable(df, connected, use_to_html, lengthMenu, monkeypatch):
     if "bigint" in df.columns:
         monkeypatch.setattr("itables.options.warn_on_int_to_str_conversion", False)
-    to_html_datatable(df, **kwargs_remove_none(lengthMenu=lengthMenu))
+    to_html_datatable(
+        df,
+        connected=connected,
+        use_to_html=use_to_html,
+        **kwargs_remove_none(lengthMenu=lengthMenu)
+    )
 
 
 def test_ordered_categories():
@@ -92,16 +102,16 @@ def test_format_column(series_name, series):
 
 
 @pytest.mark.parametrize("series_name,series", get_dict_of_test_series().items())
-def test_show_test_series(series_name, series, monkeypatch):
+def test_show_test_series(series_name, series, connected, use_to_html, monkeypatch):
     if "bigint" in series_name:
         monkeypatch.setattr("itables.options.warn_on_int_to_str_conversion", False)
-    show(series)
+    show(series, connected=connected, use_to_html=use_to_html)
 
 
-def test_show_df_with_duplicate_column_names():
+def test_show_df_with_duplicate_column_names(connected, use_to_html):
     df = pd.DataFrame({"a": [0], "b": [0.0], "c": ["str"]})
     df.columns = ["duplicated_name"] * 3
-    show(df)
+    show(df, connected=connected, use_to_html=use_to_html)
 
 
 @pytest.mark.parametrize("type", COLUMN_TYPES)