>>> zoo2.keys()
dict_keys(['A20', 'C', 'S9', 'F19'])
>>> list(zoo2.keys())
['A20', 'C', 'S9', 'F19']
>>> for k in zoo2.keys():
...     print(k)
...
A20
C
S9
F19
>>> zoo2.values()
dict_values(['tapir', 'tiger', 'dragon', 'dragon'])
>>> 'C' in zoo2
True
>>> 'C20' in zoo2
False
>>> 3 in [10,9,3,5]
True
>>> 7 in [10,9,3,5]
False
>>> len(zoo2)
4
>>> for k in zoo2:
...     print(k)
...
A20
C
S9
F19
>>> for k in zoo2:
...     print(k + ' - ' + zoo2[k])
...
A20 - tapir
C - tiger
S9 - dragon
F19 - dragon