>>> s = 'i am %s,age %d' %('cai',18)

>>> print(s)

i am cai,age 18

 

>>> s = 'i am %(n1)s,age %(n2)d' %{'n1':'cai','n2':18}

>>> print(s)

i am cai,age 18

 

>>> s = 'i am %(n1)+10s,age %(n2)d' %{'n1':'cai','n2':18}

>>> print(s)

i am    cai,age 18

 

>>> s = 'i am %(n1)+10s,age %(n2)10d' %{'n1':'cai','n2':18}

>>> print(s)

i am    cai,age     18

 

>>> s = "i am %.3f abcd" %1.2

>>> print(s)

i am 1.200 abcd 

i1 = "i am {},age {} ,{}".format('cairui',18,'kk')

print(i1)

  i am cairui,age 18 ,kk

 

i1 = "i am {0},age {1} ,{0}".format('cairui',18)

print(i1)

  i am cairui,age 18 ,cairui

 

i1 = "i am {name},age {age} ,{name}".format(name='cairui',age=18)

print(i1)

  i am cairui,age 18 ,cairui

 

i1 = "i am {:s},age {:d} ,{:f}".format('cairui',18,6.1)

print(i1)

  i am cairui,age 18 ,6.100000