1for n in range(20):
2    print('testing dict with {} items'.format(n))
3    for i in range(n):
4        # create dict
5        d = dict()
6        for j in range(n):
7            d[str(j)] = j
8        print(len(d))
9
10        # delete an item
11        del d[str(i)]
12        print(len(d))
13
14        # check items
15        for j in range(n):
16            if str(j) in d:
17                if j == i:
18                    print(j, 'in d, but it should not be')
19            else:
20                if j != i:
21                    print(j, 'not in d, but it should be')
22