Python 感叹号r !r

例子：

val = 'test'

str1 = f'str1 is {val}'
str2 = f'str2 is {val!s}'
str3 = f'str3 is {val!r}'

print(str1)
print(str2)
print(str3)

# output
# str1 is test
# str2 is test
# str3 is 'test'

可以看出!s不带引号，!r带引号(默认单引号)

其实，!s相当于str(val) !r相当于repr(val)

print(str('test'))
print(repr('test'))

#output
# test
# 'test'

具体参考Python Dunder/Magic Methods 魔法方法之

repr
str