format_mapping to transform and display None rows explicitly, but it doesn't. import polars as pl
df = pl.DataFrame(
{
"a": [[None, 1, 2, 3], [4, 5, 6, 7], None],
}
).with_row_index("i")
mo.ui.table(
df,
format_mapping={"a": lambda x: "None" if x is None else x},
)
list(map(lambda x: "None" if x is None else x, df["a"]))format_mapping, and managed (for my polars df) to get inner null elements printed. But two odd things append with format_mapping:df = pl.DataFrame(
{
"a": [[None, 1, 2, 3], [4, 5, 6, 7], None],
}
)
def fmt_mapping(x):
print(f"CALLED FOR {x}")
if isinstance(x,pl.Series):
return x.cast(pl.String).fill_null("null").str.join(",")
return x
mo.ui.table(
df,
format_mapping={"a": fmt_mapping},
)format_mapping is skipping None values. I made a PR to apply format_mapping to None values in table formatting. You should be able to use format_mapping to print the null elements in the next release.format_mapping is called twice for every elements, thanks for your experiment 🙂