n = 35 a = foo(n) a() n = 42 a()
>>> s = "%03d" >>> f = lambda x: s % x # Identical behavior for a regular function closure >>> map(f, range(10)) ['000', '001', '002', '003', '004', '005', '006', '007', '008', '009'] >>> s = "%04d" >>> map(f, range(10)) ['0000', '0001', '0002', '0003', '0004', '0005', '0006', '0007', '0008', '0009']