理解%r和%s的區別

理解%r和%s的區別

%r會重現所表達的對象，%s會將所有轉成字符串

eg1:

print('i am %s years old' % 22)
print('i am %r years old' % 22)
>>>>>>>>>>>>>>>>>>>>>>>>
i am 22 years old
i am 22 years old

eg2:

t = 'i am %d years old' % 22
print('i said %s' % t)
print('i said %r' % t)
>>>>>>>>>>>>>>>>>>>>>>>>
i said i am 22 years old
i said 'i am 22 years old'

eg3:

import datetime
d = datetime.date.today()
print('%s' % d)
print('%r' % d)
>>>>>>>>>>>>>>>>>>>>>>>>
2017-6-26
datetime.date(2017, 6, 26)