dct = {}
try:
    dct[7] = True
    print('7 in dct:', 7 in dct)
    print('0 in dct:', 0 in dct)
    print('dct.get(0):' + str(dct.get(0)))
    print('dct[0]:' + dct[0])  # raises KeyError
except Exception as e:
    print(type(e))
    print(e.args)
    print(e)
print(dct)