Python - 格式化(format())输出

Python函数format() - 格式化输出，例如

age = 25  
name = 'Caroline'  
  
print('{0} is {1} years old. '.format(name, age)) \#输出参数  
print('{0} is a girl. '.format(name))  
print('{0:.3} is a decimal. '.format(1/3)) \#小数点后三位  
print('{0:\_^11} is a 11 length. '.format(name)) \#使用_补齐空位  
print('{first} is as {second}. '.format(first=name, second='Wendy')) \#别名替换  
print('My name is {0.name}'.format(open('out.txt', 'w'))) \#调用方法  
print('My name is {0:8}.'.format('Fred')) \#指定宽度  
``` 




输出:

Caroline is 25 years old.
Caroline is a girl.
0.333 is a decimal.
_Caroline__ is a 11 length.
Caroline is as Wendy.
My name is out.txt
My name is Fred.
`