googlegantt - A Google Charts Gantt Chart API

Author: Adam Bard, http://adambard.com/

This api is designed to allow you to easily and quickly create gantt charts using the Google Charts API. You can save them as images or just produce a URL.

It works swell as long as you want things measured in days.

The method of producing such a chart is heavily influenced by this post by Dave Goerlich. Thanks, Dave.

Quick Start Example

from googlegantt import GanttChart, GanttCategory

gc = GanttChart('Test Chart', width=650, height=200, progress=(2011, 02, 27))

on_time = GanttCategory('On Time', '0c0')
late = GanttCategory('Late', 'c00')
upcoming = GanttCategory('Upcoming', '00c')

t1 = gc.add_task('Late Task', (2011, 02, 20), (2011, 02, 25), category=late)
t2 = gc.add_task('On Time Task', depends_on=t1, duration=3, category=on_time)
t3 = gc.add_task('Future Task', depends_on=t2, duration=7, category=upcoming)

url = gc.get_url()
image = gc.get_image()

Produces:

Features

• Optional Progress indicator shades the elapsed area of the chart.
• Flexible chart width and height.
• Specify task colors using css rules.
• Flexibly specify dates using datetime.date objects, or tuples.
• Produce a Google Chart url, or a png image (requires PIL).
• Date span is automatically computed from tasks.

Classes

There are 3 primary classes involved in the creation of a chart.

GanttChart

GanttChart(title,[ **kwargs])

Produce a Gantt Chart.

Keyword Arguments:

• width The width of the chart.
• height The height of the chart.
• progress A date representing the current time, to produce a shaded 'elapsed' region.

Example initialization:

gc = GanttChart('Test Chart', width=600, height=200, progress=(2011, 02, 27))

Methods:

• GanttChart.get_url() Get a Google Charts URL of the chart, for direct access
• GanttChart.get_image() Get a PIL Image object, to be manipulated
• GanttChart.get_image(save_path) Save a .png image to save_path

GanttCategory

Optional in common usage. Represents a class of Tasks with a color and a title.

GanttCategory(title[, color])

Produce a category object with a given color. Color is specified using a hex string, and will be converted to an 8-byte rgba hex color string expected by Google Charts from any of the following formats:

• 3-byte, e.g. 'f00' => 'FF0000FF'
• 4-byte, e.g. 'f00c' => 'FF0000CC'
• 6-byte, e.g. 'ff0000' => 'FF0000FF'
• 8-byte

GanttTask

Represents a single bar in the chart. Must have a specified start and end date, although these can be computed in different ways.

GanttTask(title[, start_date=None, end_date=None[, **kwargs]])

Keyword Arguments:

• start_date The start date of the task
• end_date The end date of the task
• duration The duration, in days, of the task. May be used instead of end_date
• depends_on A GanttTask that must be completed before this one can begin. May be used instead of start_date
• category A GanttCategory to apply to this task.
• color A quick way to specify color. Don't use this when you have categories declared, you will get blank legend entries.

Either start_date or depends_on must be specified. Same with end_date and duration.

If both start_date and depends_on are specified, depends_on is used.

If both end_date and duration are specified, duration is used.

More Information

Check out the doctests in the gantt.py file for more information.

License

Copyright (c) 2011 Adam Bard (adambard.com)

Licensed under the MIT License: http://www.opensource.org/licenses/mit-license