reportlab_argument_handling.py

# Example showing how Python default argument handling causes a bug
# when using the ReportLab library for Python. Tested against
# ReportLab 2.3.
#
# See http://gist.github.com/246507 for a generic Python example.

from reportlab.platypus import *


def main():
    template1 = PageTemplate(id='template1')
    template1.frames.append(Frame(0, 0, 10, 20, id='t1_f1'))
    template1.frames.append(Frame(30, 40, 50, 60, id='t1_f2'))

    template2 = PageTemplate(id='template2')
    template2.frames.append(Frame(1, 1, 11, 21, id='t2_f1'))
    template2.frames.append(Frame(32, 42, 52, 62, id='t2_f2'))

    # I expect to see two frames, but there are actually four.
    # All of the frames from template1 have been copied into
    # template2.
    print [f.id for f in template2.frames]


if __name__ == '__main__':
    main()