030 向字符串的format方式传递参数有几种方式

1. 字符串的format方法有几种指定参数方式

1. 默认方式（传入的参数与{}一一对应）

2. 命名参数

3. 位置参数

 

2. 通过代码详细描述

s1 = 'Today is {}, the temperature is {} degrees.'
print(s1.format('Saturday', 24))

s2 = 'Today is {day}, the temperature is {degree} degrees.'
print(s2.format(degree=30, day='Saturday'))

s3 = 'Today is {week}, {}, the {} temperature is {degree}'
print(s3.format('abcd', 1234, degree=24, week='Sunday'))

s4 = 'Today is {week}, {1}, the {0} temperature is {degree} degrees'
print(s4.format('abcd', 1234, degree=24, week='Sunday'))

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

    def getName(self):
        return 'Bill'

person = Person()
# s5 = 'My name is {p.getName()}, my age is {p.age}.'
# print(s5.format(p = person))
# AttributeError: 'Person' object has no attribute 'getName()'

# 只能访问属性，不能访问方法
s5 = 'My name is {p.name}, my age is {p.age}.'
print(s5.format(p = person))

 

Today is Saturday, the temperature is 24 degrees.
Today is Saturday, the temperature is 30 degrees.
Today is Sunday, abcd, the 1234 temperature is 24
Today is Sunday, 1234, the abcd temperature is 24 degrees
My name is Bill, my age is 20.

 

format方法使用一对大括号{}指定字符串中需要替换的部分。

使用数字，表示引用特定位置的参数值

使用标识符，根据名字设置位置的占位符