格式化字符串，,>>> a,b=5,42

格式化字符串，,>>> a,b=5,42

>>> a,b=5,42>>> print(a,b)5 42>>> 'this is {}, and that is {}'.format(a,b)'this is 5, and that is 42'>>> s = 'this is {}, and that is {}'>>> s'this is {}, and that is {}'>>> s.format(a, b)'this is 5, and that is 42'>>> id(s)64800544>>> new = s.format(a,b)>>> id(new)64454464>>> 'this is {1}, and that is {0}'.format(a,b)'this is 42, and that is 5'>>> 'this is {bob} and that is {fred}'.format(bob=a, fred=b)'this is 5 and that is 42'>>> d = dict(bob=a,fred=b)>>> 'this is {bob} and that is {fred}'.format(**d)'this is 5 and that is 42'>>>