How to add signs to the fractional part?

Question

Python

Perhaps a stupid question, but you need to add fractional signs to the number, how to do this, I googled, but did not find it?
Example (from 1024 get 1024.000)

Answer 1

i = float(1024).
Or do you need a formatted output?

Answer 2

print '%.3f' % 1024

Answer 3

a = float(1024.123)