It's been a while since I've been studying some python code that I come across this situation.
Some people format the code using ".format":
fruta = "Maça"
print("Eu gosto de {0}!".format(fruta))
And others use the "%"
fruta = "Maça"
print("Eu gosto de %s!" % fruta)
My question is:
Is there any difference between these two forms? Whether it's the performance issue or something?
Yes, there are several differences, several improvements, and the new style is much more elegant and pythonic in my opinion. I have not read it anywhere, it's just flattering, but I believe the old style is maintained for compatibility with legacy code.
I put some differences below, in fact, I chose those that I could not do in the old format, of course I did not put all of them, but only the ones I found most interesting, for access to all the features, get the documentation.
With the new style you can clarify the position of the argments:
'{1} {0}'.format('Um', 'Dois')
Dois Um
Choose a pad character:
'{:_<9}'.format('teste')
teste____
Centralization:
'{:^10}'.format('teste')
teste
Arguments in keys:
'{nome} {sobrenome}'.format{sobrenome='Silva', nome='José')
'José Silva'
Access to data structures (dict and list in the example):
pessoa = {'nome': 'José', 'sobrenome': 'Silva'}
'{p[sobrenome]} {p[nome]}'.format(p=pessoa)
'Silva José'
data = [9, 2, 43, 18, 32, 77, 99]
'{d[3]} {d[6]}'.format(d=data)
'18,99'