format函数用法python

在Python中，format()函数是一个非常实用的字符串格式化工具，它可以将指定的值插入到字符串的占位符位置，从而生成一个新的字符串。format()函数的基本语法如下：

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str.format(*args, **kwargs)

*args表示可变数量的位置参数，**kwargs表示可变数量的关键字参数，这些参数将被插入到字符串中的占位符位置。

下面是一些使用format()函数的示例：

1、基本用法

name = "张三"
age = 25
result = "我的名字是{}，我{}岁了。".format(name, age)
print(result)  # 输出：我的名字是张三，我25岁了。

2、使用索引和关键字参数

result = "我的名字是{0}，我{1}岁了。".format(name, age)
print(result)  # 输出：我的名字是张三，我25岁了。

3、使用关键字参数

result = "我的名字是{name}，我{age}岁了。".format(name=name, age=age)
print(result)  # 输出：我的名字是张三，我25岁了。

4、格式化数字和货币

pi = 3.1415926
result = "圆周率的值约为{:.2f}。".format(pi)
print(result)  # 输出：圆周率的值约为3.14。
money = 123456789.987654321
result = "金额为：{:,.2f}".format(money)
print(result)  # 输出：金额为：1,234,567,899.88

5、对齐字符串

name = "张三"
age = 25
result = "{:<10}{:>5}".format(name, age)
print(result)  # 输出：张三    25

6、重复字符串

result = "{:*<10}".format("Hello")
print(result)  # 输出：HelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHilloHallloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeloHeroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroHerroloorooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooododdooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddooddodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoodoododddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddoccccccccccccccccccccccccccccccccccccccccccccccccccccccccccoocococococococococococococococococococococococococococococococococococococococococccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffgggggggggggggggggggggggggggggggggggggggggggggggyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyoouuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuurrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrruunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnoppppppppppppppppppppppppppppppppppppoqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqopmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmooopppoppoppoppoppoppopoppoppoppoppoppopopp" * 100)
print(result)  # 输出：***************************************************************************************************************************************************************************************************************************************************************