Python str.format函数的用法详解

Python 笔记

一、基本用法

    
print("My name is {}".format("John"))
print("I am {} years old".format(20))
    

    
My name is John
I am 20 years old
    

二、通过位置传递参数

    
print("Hello, {} {}. Nice to meet you!".format("Mr.", "Smith"))
    

    
Hello, Mr. Smith. Nice to meet you!
    

三、通过名称传递参数

    
print("Hello, {first} {last}. Nice to meet you!".format(first="John", last="Doe"))
    

    
Hello, John Doe. Nice to meet you!
    

四、使用字典传递参数

    
person = {"first": "John", "last": "Doe"}
print("Hello, {first} {last}. Nice to meet you!".format(**person))
    

    
Hello, John Doe. Nice to meet you!
    

五、控制输出格式

    
print("The value of X is {:0.2f}".format(3.14159))
    

    
The value of X is 3.14
    

六、对齐文本

    
print("{:<10}{}".format("Left", "Right"))
print("{:>10}{}".format("Left", "Right"))
    

    
Left      Right
      LeftRight
    

七、使用占位符代表大括号

    
print("{{ {} }}".format("Hello"))
    

    
{ Hello }
    

八、结论