insert_nan.py

import numpy as np
from bokeh.io import show, output_notebook
from bokeh.plotting import figure
from bokeh import events
from bokeh.models import CustomJS, ColumnDataSource
output_notebook()

import pandas as pd

time1 = pd.date_range("2018/01/01", "2018/01/05", freq="h")
time2 = pd.date_range("2018/01/07", "2018/01/08", freq="h")
time = pd.concat([time1.to_series(), time2.to_series()])
v = np.random.randn(len(time))
df = pd.DataFrame({"value":v}, index=time)

loc = np.where((df.index[1:] - df.index[:-1]).total_seconds() > 10000)[0]

df2 = df.reindex(index=df.index.union(df.index[loc].shift(1, freq="s")))

source = ColumnDataSource(data=dict(x=df2.index, y=df2["value"]))
fig = figure(plot_height=250, x_axis_type='datetime')
fig.line("x", "y", source=source)
show(fig)