How to do a threshold line on a bar chart using plotly - python-3.x

Question

Currently written this code that produces a bar chart but would like to add a threshold line. Could anyone help me please?
def make_bar_chart(data):
"""Takes a list of dicts with a time and price"""
# Times
chart_x = []
# Prices
chart_y = []
# Create the relevant arrays
for item in data:
chart_x.append(item["time"])
chart_y.append(item["price"])
# Make the chart
the_graph = Bar(x = chart_x, y = chart_y , name = "Stocks")
graph_data = Data([the_graph])
the_layout = Layout(title = "Stocks", xaxis = dict(title = "Time"), yaxis = dict(title = "Price"))
the_figure = Figure(data = graph_data, layout = the_layout)
plotly.offline.plot(the_figure, filename = "stocks.html")

Answer 1

Try something like this. In plotly it seems that lines are provided via shapes.
the_layout = Layout(title = "Stocks",
xaxis = dict(title = "Time"),
yaxis = dict(title = "Price"),
shapes=[
{
'type': 'line',
'xref': 'paper',
'x0': 0,
'y0': 100, # use absolute value or variable here
'x1': 1,
'y1': 100, # ditto
'line': {
'color': 'rgb(50, 171, 96)',
'width': 1,
'dash': 'dash',
},
},
],
)
I haven't tested this as you haven't provided sample data. Well done for supplying code on your first question, but on Stack Overflow it's best to provide a completely self-contained example that people can copy and run 'as is.'