Based on the comments.
Initially I thought that you wanted to change the current directory in your machine. Hence, I referenced this question where we can read answers like this one which states that the desired operation can be achieved with
import os
os.chdir(path)
OFC in your particular case you'd want to change the path right before downloading the file.
Since you added more clarification with
What if I want to make it an app and in others computer how can I know
there donwload directory folder?
that'd be a different scenario and there's an already existing question for that too with an already accepted answer.
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