格式化输出

程序中经常会有这样场景：

　　要求用户输入信息，然后打印成固定的格式

比如：

name1 = '小李子'
name2 = '小橙子'
num = 123.123456
age = 25
age1 = 34
age2 = 55　　

#占位符:%s,%d,%f

>>> res = 'my name is %.2f'
>>> res = 'my name is %s'
>>> print(res % name1)
my name is 小李子
>>> print(res % name2)
my name is 小橙子
>>> print(res)
my name is %s
>>> res = 'my name is %s, my age is %s' % (name1,age)
>>> print(res)
my name is 小李子, my age is 25
>>> res = 'my num is %d'
>>> print(res % num)
my num is 123
>>> res = 'my num is %s'
>>> print(res % num)
my num is 123.123456
>>> res = 'my num is %f'
>>> print(res % num)
my num is 123.123456
>>> res = 'my num is %.2f'
>>> print(res % num)
my num is 123.12　　

# format（起占位符作用）

>>> res = 'my name is {}, my age is {}'.format(name1, age)
>>> print(res)
my name is 小李子, my age is 25
>>> res = 'my name is {0}, my age is {1}, his age is {3}, her age is {3}, its age is {2}'.format(name1,age,age1,age2)
>>> print(res)
my name is 小李子, my age is 25, his age is 55, her age is 55, its age is 34
>>> res = 'my name is {name}, my age is {age}'.format(name=name1, age=age)
>>> print(res)
my name is 小李子, my age is 25

来源：https://www.cnblogs.com/twoo/p/11642774.html