>>> """
===============
Basic pie chart
===============

Demo of a basic pie chart plus a few additional features.

In addition to the basic pie chart, this demo shows a few optional features:

* slice labels
* auto-labeling the percentage
* offsetting a slice with "explode"
* drop-shadow
* custom start angle

Note about the custom start angle:

The default ``startangle`` is 0, which would start the "Frogs" slice on the
positive x-axis. This example sets ``startangle = 90`` such that everything is
rotated counter-clockwise by 90 degrees, and the frog slice starts on the
positive y-axis.
"""
... import matplotlib.pyplot as plt
... 
... # Pie chart, where the slices will be ordered and plotted counter-clockwise:
... labels = 'Frogs', 'Hogs', 'Dogs', 'Logs'
... sizes = [15, 30, 45, 10]
... explode = (0, 0.1, 0, 0)  # only "explode" the 2nd slice (i.e. 'Hogs')
... 
... fig1, ax1 = plt.subplots()
... ax1.pie(sizes, explode=explode, labels=labels, autopct='%1.1f%%',
...         shadow=True, startangle=90)
... ax1.axis('equal')  # Equal aspect ratio ensures that pie is drawn as a circle.
... 
... plt.show()
... 
... #############################################################################
... #
... # .. admonition:: References
... #
... #    The use of the following functions, methods, classes and modules is shown
... #    in this example:
... #
... #    - `matplotlib.axes.Axes.pie` / `matplotlib.pyplot.pie`
...