1.打印字符串
>>> print "I'm %s" % ("jihite")
I'm jihite
2.打印整数
>>> print "I'm %d years old" % (17)
I'm 17 years old
3.打印浮点数
>>> print "π=%f" % (3.1415926)
π=3.141593
4.打印浮点数（指定保留小数点位数）
>>> print "π=%.3f" % (3.1415926)
π=3.142
5.指定占位符宽度
>>> print "NAME:%8s AGE:%8d WEIGHT:%8.2f" % ("jihite", 17, 62.2)
NAME: jihite AGE: 17 WEIGHT: 62.20
6.指定占位符宽度（左对齐）
>>> print "NAME:%-8s AGE:%-8d WEIGHT:%-8.2f" % ("jihite", 17, 62.2)
NAME:jihite AGE:17 WEIGHT:62.20
7.指定占位符（只能用0当占位符）
>>> print "NAME:%-8s AGE:%08d WEIGHT:%08.2f" % ("jihite", 17, 62.2)
NAME:jihite AGE:00000017 WEIGHT:00062.20
8.科学计数法
>>> format(0.0000023, '.2e')
'2.30e-06'
>>> format(0.23, '.2e')
'2.30e-01'
