The if-else cases in lsqr.py were not exhaustive. They become exhaustive by changing ab > aa to ab >= aa.
from dionysus import Simplex, ZigzagPersistence, \
vertex_cmp, data_cmp \
# ,enable_log
complex = {Simplex((0,), 0): None, # A
Simplex((1,), 1): None, # B
Simplex((2,), 2): None, # C
Simplex((0,1), 2.5): None, # AB
Simplex((1,2), 2.9): None, # BC
Simplex((0,2), 3.5): None, # CA
Simplex((0,1,2), 5): None} # ABC
print "Complex:"
for s in sorted(complex.keys()): print s
print
#enable_log("topology/persistence")
zz = ZigzagPersistence()
# Add all the simplices
b = 1
for s in sorted(complex.keys(), data_cmp):
print "%d: Adding %s" % (b, s)
i,d = zz.add([complex[ss] for ss in s.boundary], b)
complex[s] = i
if d: print "Interval (%d, %d)" % (d, b-1)
b += 1
# Remove all the simplices
for s in sorted(complex.keys(), reverse = True):
print "%d: Removing %s" % (b, s)
d = zz.remove(complex[s], b)
del complex[s]
if d: print "Interval (%d, %d)" % (d, b-1)
b += 1