micropython/tests/basics/dict2.py

# using strings as keys in dict

d = {'1': 1, '2': 2}
print(d['1'], d['2'])

d['3'] = 3
print(d['1'], d['2'], d['3'])

d['2'] = 222
print(d['1'], d['2'], d['3'])

d2 = dict(d)
print('2' in d2)
print(id(d) != id(d2), d == d2)