字符串的format方法有机制制定参数方式

1. 默认方式(传入参数与{} 一一对应)
2. 命名参数与位置参数{2}

详细描述字符串format方法如何格式化字符串

• 不带命名参数的format

s1 = 'Today is {}, the temprature is {} degrees.'

print(s1.format('Saturday',24))

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• 带上命名参数的format

s2 = 'Today is {week}, the temprature is {degree} degrees.'

print(s2.format(degree = 30, week = 'Monday'))

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• 混合使用参数的format

s3 = 'Today is {week}, the {} temprature is {degree} degrees.'
print(s3.format('abcd',week = 'Sunday',degree=15))

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• 混合使用参数format,使用索引引入到参数中

1. 索引加入以后，参数会根据索引进行传参，不会根据自身顺序输出

s4 = 'Today is {week}, the {0}, new {1} temprature is {degree} degrees.'
print(s4.format('abcd','xyz',week = 'Sunday',degree=15))

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s4 = 'Today is {week}, the {1}, new {0} temprature is {degree} degrees.'
print(s4.format('abcd','xyz',week = 'Sunday',degree=15))

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• 可以添加一个函数

class Person:
    def __init__(self):
        self.age = 20
        self.name = 'Bill'
        
person = Person()

s5 = "My name is {p.name}, my age is {p.age}"
print(s5.format(p = person))

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总结

Format方法使用一对大括号{} 制定字符串需要替换的部分，在大括号中可以使用数字，标识符，参数名设置相应的占位符

加油 2020-3-1