Plotly python axix 代码格式问题与具有毫秒的纪元时间

Question

my x axis values are in epoch time with milliseconds. When I try to set the xaxis ticker to a more readable format such as:

fig.update_layout(
            xaxis = {'type': 'date','tickformat': '%H:%M:%S'},
            )

The date doesn't come through correctly as expected. The year, day, hour, are all incorrect. I cannot find the proper way to do this with plotly python. If someone could provide an example that would be great.

Answer 1

Haven't had much luck with millisecond timestamps either. One solution could be to pre-format before going to Plotly. This slows down performance, but there are certain formats Plotly recognizes.

Not assuming you are using pandas as your inputs, but you can build the format like so:

        df2[xaxis_name] = pd.to_datetime(df[xaxis_name], unit='ms').dt.date

https://plotly.com/python/time-series/

Then you can further refine it with:

https://plotly.com/python/reference/#layout-xaxis-tickformat

Such as:

fig.update_xaxes(
           tickformat = "%b-%Y"
        )

Worked for me.

Plotly auto-sets the axis type to a date format when the corresponding data are either ISO-formatted date strings or if they're a date pandas column or datetime NumPy array.