>>> t1 = ("A", "B", "C")
>>> t2 = ("1", "2", "3")
>>> [x + y for x in t1 for y in t2]
['A1', 'A2', 'A3', 'B1', 'B2', 'B3', 'C1', 'C2', 'C3']
>>> [[x + y for y in t2] for x in t1]
[['A1', 'A2', 'A3'], ['B1', 'B2', 'B3'], ['C1', 'C2', 'C3']]
>>> x = _ # assign x to the last value
>>> for row in x:
... print " ".join(row)
...
A1 A2 A3
B1 B2 B3
C1 C2 C3
>>> for x in t1:
... for y in t2:
... print x + y, # notice the comma, special print-statement syntax
... print
A1 A2 A3
B1 B2 B3
C1 C2 C3
[..]
используется здесь как список пониманий .