In [1]: "%(name)s is %(age)s" % {"name":"bob", "age": 12} Out[1]: 'bob is 12' In [2]: "%s is %s" % ("bob", "13") Out[2]: 'bob is 13' In [6]: "{0} is {1}".format("bob", "14") Out[6]: 'bob is 14' In [7]: "{name} is {age}".format(name="bob",age="15") Out[7]: 'bob is 15'