Empty bar chart when plotting a single point using a date range

[GabrielPereyra]

plotly==3.10.0

import datetime
from plotly.offline import plot

plot({
    'data': [{
        'x': [datetime.datetime(2019, 6, 6)],
        'y': [5],
        'type': 'bar'
    }],
    'layout': {
        'xaxis': {
            'range': [datetime.datetime(2019, 6, 1), datetime.datetime(2019, 6, 30)]
        }
    }
})

The following code leads to an empty chart. If I plot a single point with numeric values instead of datetimes, change the type to scatter, add a another datapoint or double-click the chart to zoom in, I get the expected behavior.

[jonmmease]

Thanks for the report @GabrielPereyra,

The problem here is that if you specify only a single bar, then you'll need to specify the bar width manually. The bar width is specified using the width parameter, and for a date axis, the width is specified in milliseconds. So here's an example of specifying a bar width of 1 day.

import datetime
from plotly.offline import plot
import plotly.graph_objs as go

fig = go.FigureWidget({
    'data': [{
        'x': [datetime.datetime(2019, 6, 6)],
        'y': [5],
        'type': 'bar',
        'width': 24*60*60*1000
    }],
    'layout': {
        'xaxis': {
            'range': [datetime.datetime(2019, 6, 1), datetime.datetime(2019, 6, 30)]
        }
    }
})
plot(fig)

If you have multiple bars, then plotly.js can automatically compute reasonable bar widths. But if you have only a single bar then you need to specify the width yourself. Does that make sense?