Should we use python for making intelligent android apps or we have to use java ?

Answer 1

You can! You can use Kivy https://kivy.org/#home which covers the widely used platforms. They have documentation to create your .apk file. I wish you success!

Answer 2

://You can create without using java, with some powerful python libraries
https://www.sololearn.com/discuss/1586820/?ref=app