gantt.md

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jupytext kernelspec language_info plotly notebook_metadata_filter text_representation all extension format_name format_version jupytext_version .md markdown 1.2 1.4.2 display_name language name Python 3 python python3 codemirror_mode file_extension mimetype name nbconvert_exporter pygments_lexer version name version ipython 3 .py text/x-python python python ipython3 3.7.7 description display_as language layout name order page_type permalink thumbnail How to make Gantt Charts in Python with Plotly. Gantt Charts use horizontal bars to represent the start and end times of tasks. basic python base Gantt Charts 9 u-guide python/gantt/ thumbnail/gantt.jpg

A Gantt chart is a type of bar chart that illustrates a project schedule. The chart lists the tasks to be performed on the vertical axis, and time intervals on the horizontal axis. The width of the horizontal bars in the graph shows the duration of each activity.

Gantt Charts and Timelines with plotly.express

Plotly Express is the easy-to-use, high-level interface to Plotly, which operates on a variety of types of data and produces easy-to-style figures. With px.timeline (introduced in version 4.9) each data point is represented as a horizontal bar with a start and end point specified as dates.

The px.timeline function by default sets the X-axis to be of type=date, so it can be configured like any time-series chart.

Plotly Express also supports a general-purpose px.bar function for bar charts.

import plotly.express as px
import pandas as pd

df = pd.DataFrame([
    dict(Task="Job A", Start='2009-01-01', Finish='2009-02-28'),
    dict(Task="Job B", Start='2009-03-05', Finish='2009-04-15'),
    dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30')
])

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Task")
fig.update_yaxes(autorange="reversed") # otherwise tasks are listed from the bottom up
fig.show()

px.timeline supports discrete color as above, or continuous color as follows.

import plotly.express as px
import pandas as pd

df = pd.DataFrame([
    dict(Task="Job A", Start='2009-01-01', Finish='2009-02-28', Resource="Alex"),
    dict(Task="Job B", Start='2009-03-05', Finish='2009-04-15', Resource="Alex"),
    dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30', Resource="Max")
])

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Task", color="Resource")
fig.update_yaxes(autorange="reversed")
fig.show()

import plotly.express as px
import pandas as pd

df = pd.DataFrame([
    dict(Task="Job A", Start='2009-01-01', Finish='2009-02-28', Completion_pct=50),
    dict(Task="Job B", Start='2009-03-05', Finish='2009-04-15', Completion_pct=25),
    dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30', Completion_pct=75)
])

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Task", color="Completion_pct")
fig.update_yaxes(autorange="reversed")
fig.show()

It is also possible to have multiple bars on the same horizontal line, say by resource:

Note: When setting color to the same value as y, autorange should not be set to reverse, so as to list the value of the Y axis in the same order as the legend entries.

import plotly.express as px
import pandas as pd

df = pd.DataFrame([
    dict(Task="Job A", Start='2009-01-01', Finish='2009-02-28', Resource="Alex"),
    dict(Task="Job B", Start='2009-03-05', Finish='2009-04-15', Resource="Alex"),
    dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30', Resource="Max")
])

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Resource", color="Resource")
fig.show()

Deprecated Figure Factory

Prior to the introduction of plotly.express.timeline() in version 4.9, the recommended way to make Gantt charts was to use the now-deprecated create_gantt() figure factory, as follows:

import plotly.figure_factory as ff

df = [dict(Task="Job A", Start='2009-01-01', Finish='2009-02-28'),
      dict(Task="Job B", Start='2009-03-05', Finish='2009-04-15'),
      dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30')]

fig = ff.create_gantt(df)
fig.show()

Group Tasks Together

The following example shows how to use the now-deprecated create_gantt() figure factory to color tasks by a numeric variable.

import plotly.figure_factory as ff

df = [dict(Task="Job-1", Start='2017-01-01', Finish='2017-02-02', Resource='Complete'),
      dict(Task="Job-1", Start='2017-02-15', Finish='2017-03-15', Resource='Incomplete'),
      dict(Task="Job-2", Start='2017-01-17', Finish='2017-02-17', Resource='Not Started'),
      dict(Task="Job-2", Start='2017-01-17', Finish='2017-02-17', Resource='Complete'),
      dict(Task="Job-3", Start='2017-03-10', Finish='2017-03-20', Resource='Not Started'),
      dict(Task="Job-3", Start='2017-04-01', Finish='2017-04-20', Resource='Not Started'),
      dict(Task="Job-3", Start='2017-05-18', Finish='2017-06-18', Resource='Not Started'),
      dict(Task="Job-4", Start='2017-01-14', Finish='2017-03-14', Resource='Complete')]

colors = {'Not Started': 'rgb(220, 0, 0)',
          'Incomplete': (1, 0.9, 0.16),
          'Complete': 'rgb(0, 255, 100)'}

fig = ff.create_gantt(df, colors=colors, index_col='Resource', show_colorbar=True,
                      group_tasks=True)
fig.show()

Color by Numeric Variable

The following example shows how to use the now-deprecated create_gantt() figure factory to color tasks by a numeric variable.

import plotly.figure_factory as ff

df = [dict(Task="Job A", Start='2009-01-01', Finish='2009-02-28', Complete=10),
      dict(Task="Job B", Start='2008-12-05', Finish='2009-04-15', Complete=60),
      dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30', Complete=95)]

fig = ff.create_gantt(df, colors='Viridis', index_col='Complete', show_colorbar=True)
fig.show()

Reference

For more info on ff.create_gantt(), see the full function reference