Perspective does not show data if datetime column contains NaT

[MarcSkovMadsen]

I'm on Panel==1.3.6 trying to use Perspective.

import pandas as pd
import pandas as pd
import numpy as np

# Create a sample DataFrame with a datetime column
data = {'Datetime': pd.to_datetime(['2022-01-01', '2022-01-02', '2022-01-03', '2022-01-04'])}
df = pd.DataFrame(data)

# Assign NaN values to specific rows or cells
df.loc[1, 'Datetime'] = np.nan
df.loc[3, 'Datetime'] = np.nan
print(df)
print(df.dtypes)

import panel as pn
pn.extension("perspective")

pn.pane.Perspective(df, sizing_mode="stretch_width").servable()

format_cell.js:71  Uncaught (in promise) RangeError: Invalid time value

Hacky Workaround

Replace the NaT value with a valid timestamp

import pandas as pd
import pandas as pd
import numpy as np

# Create a sample DataFrame with a datetime column
data = {'Datetime': pd.to_datetime(['2022-01-01', '2022-01-02', '2022-01-03', '2022-01-04'])}
df = pd.DataFrame(data)

# Assign NaN values to specific rows or cells
df.loc[1, 'Datetime'] = np.NAN
df.loc[3, 'Datetime'] = np.NAN
print(df)
print(df.dtypes)

NAT_TIMESTAMP = pd.Timestamp('1980-01-01')

def _clean_for_perspective(data: pd.DataFrame):
    datetime_columns = data.select_dtypes(include='datetime64[ns]').columns
    data[datetime_columns] = data[datetime_columns].fillna(NAT_TIMESTAMP)
    return data

df = _clean_for_perspective(df)

import panel as pn
pn.extension("perspective")

pn.pane.Perspective(df, sizing_mode="stretch_width").servable()