Importing Fraction from fractions to give a fractional representation of a real number, but giving responses quite complicated which seems very simple by the paper-pen method.
Fractions(.2) giving answer 3602879701896397/18014398509481984,
which is 0.20000000000000001110223024625157, almost .2, but I want it to be simply 1/5.
I know there's limit() for this use, but what I simply required is smallest numerator and denominator which gives the exact real number bcoz I am dealing with a lot of numbers in a big range so i cant use same limit() argument for all.

You can use the Fraction class to represent 0.2, and you can access the numerator and denominator as follows:

>>> from fractions import Fraction
>>> f = Fraction(1, 5)
>>> f.numerator
1
>>> f.denominator
5

Hope it helps.