普通字符串和以'％s'格式化的字符串有什么区别？

Question

What's the difference between a normal string and a string formatted by '%s', because their results are different, like the following:

# It's ok
>>> "{%s}" % ' and '.join(['nice','good','perfect'])
'{nice and good and perfect}'

# It's not ok
>>> "{' and '}".join(['nice','good','perfect'])
"nice{' and '}good{' and '}perfect"

Answer 1

Your first example,

"{%s}"%' and '.join(['nice','good','perfect'])

joins the list with the given string, ' and ' then puts that in place of the %s

Your second example,

"{' and '}".join(['nice','good','perfect'])

joins the list with the given string, {' and '} . So as you can see, these are two completely different operations, which is why you get a different output.

Answer 2

Change the code as

"{" + " and ".join(['nice','good','perfect']) + "}"

Output:

'{nice and good and perfect}'