for n in range(20):
print('testing dict with {} items'.format(n))
for i in range(n):
# create dict
d = dict()
for j in range(n):
d[str(j)] = j
print(len(d))
# delete an item
del d[str(i)]
# check items
if str(j) in d:
if j == i:
print(j, 'in d, but it should not be')
else:
if j != i:
print(j, 'not in d, but it should be')