How Would One Go About Creating A Graph Like This In Plotly/Pandas?

Question

I would like to recreate following image in Plotly and Pandas. but I'm not sure how.

I have looked into using Gantt Graphs but every time I see one the timeline is going along the x axis and not the y axis as in this picture. Does anyone have any tips?

Answer 1

I don't think Plotly Gantt charts can easily be rotated, but the most important information is the duration of time for each bar. We can think about your graph as a vertical bar chart where each bar is the duration of time, using the starting times as a base (or offset) for each bar.

I would recommend entering your times in the 24-hour notation so that durations can be calculated correctly.

You can use the following as a template for the graph you want to create (changing the color scheme, font size, etc as desired). I have left the y-axis labels so that it's easier to understand my code (we can see hour 23 of the day is actually hour -1 inside the figure itself, and hour 0 of the day remains the same), but you can hide the y-axis labels in your final figure.

import pandas as pd
import plotly.graph_objects as go
from datetime import datetime

df = pd.DataFrame({
    'start': ['2024-06-17 00:04', '2024-06-18 00:24', '2024-06-18 23:54', '2024-06-19 23:59'],
    'end': ['2024-06-17 08:18', '2024-06-18 09:05', '2024-06-19 09:02', '2024-06-20 08:13'],
})

df['start'] = pd.to_datetime(df['start'])
df['end'] = pd.to_datetime(df['end'])
df['duration'] = df['end'] - df['start']

fig = go.Figure()

def get_exact_hour(ts):
    ## we want 23:54 to become -1 on the graph
    if ts.hour > 12:
        hour = ts.hour - 24
    else:
        hour = ts.hour
    minute = ts.minute
    return hour + minute/60

def convert_duration_to_hours(td: pd.Timedelta):
    hours = duration.seconds // 3600
    minutes =  (duration.seconds % 3600) / 60
    return hours + minutes/60

for start, end, duration in df.itertuples(index=False):
    day_rounded = start.round('1d') - pd.Timedelta("1D")
    day_name = day_rounded.day_name()
    day_number = day_rounded.day
    day_string = f"{day_name} </br></br> {day_number}"
    start_hour = get_exact_hour(start)
    end_hour = get_exact_hour(end)
    duration_in_hours = convert_duration_to_hours(duration)

    fig.add_trace(
        go.Bar(
            x=[day_string],
            y=[duration_in_hours],
            base=[start_hour],
            marker=dict(color='lightblue'),
        )
    )

    ## add start and end times text annotations
    start_time_formatted = start.strftime("%I:%M")
    end_time_formatted = end.strftime("%I:%M")
    padding = 0.2

    fig.add_trace(
        go.Scatter(
            x=[day_string],
            y=[start_hour-padding],
            mode='text',
            text=[start_time_formatted],
        )
    )

    fig.add_trace(
        go.Scatter(
            x=[day_string],
            y=[end_hour+padding],
            mode='text',
            text=[end_time_formatted],
        )
    )

## prettify the chart
fig.update_xaxes(type='category')
fig.update_layout(
    template='plotly_dark',
    title='TIME IN BED',
    barcornerradius=15,
    showlegend=False
)
fig.show()