can I create a valid address (without private key and public key) with a specific string?
I mean python 3 here and maybe some brute-force method?
I think you are simply looking for something like this.
import secp256k1 as ice
ice.create_burn_address('ADayWiLLcomeWheniceLandisGoingToSoLvebitCoinPuzzLe', 'X')
Result :
['1ADayWiLLcomeWheniceLandisXXVF7Q3', '1GoingToSoLvebitCoinPuzzLeXXxuijG']
If the String is bigger you will get a list of address output. Otherwise it will be just 1 address. Example
ice.create_burn_address('iceLandxxxxxxBTC', 'Z')
'1iceLandxxxxxxBTCZZZZZZZZZZae8Au3'
Is that what you want ?