Python 字面量插值的方法

定义：

就是讲变量、常量以及表达式插入的一种技术，它可以解决字符串拼接的问题，以下3种方法可实现：

• 格式化输出  %s %d  %f

name="lily"
age=3
num=3.14
print("my name is %s" %name)
print("my name is %s,my age is %d,num is %f" %(name,age,num))

• string.format()  拼接字符串、列表、字典

name="lily"
age=3
num=3.14

dict1={"name":"meimei","age":12}

print("my name is {},age is {},num is {} ".format(name,age,num))
print("my name is {name},age is {age},my friend is {friend} ".format(name=name,age=age,friend=dict1["name"]))

print("my name is {1},age is {0},num is {0}" .format(age,name)) li=[1,2,3,4] print("we are the {0} and {1}".format(*li)) # * 列表解包 dict1={"name":"lily","age":12} print("my name is {name},age is {age}" .format(**dict1)) # ** 字典解包

• Formatted string literals 字符串格式化机制

使用方法 ： f"{变量名}"

注意： 大括号里面可以是表达式或者函数

大括号内不能转义，不能使用“\”; 需要使用转义时放在大括号外面

name="lily"
li=[1,2,3,4]
dict1={"name":"meimei","age":12}
print(f"my name is {name}, age is {li[2]}, my firend is {dict1[name]}")
print(f"my name is {name.upper()}")
print(f"result is {(lambda x:x+1)(2)}")