How do I pass a fraction to python as an exponent in order to calculate the nth root of an integer?

I'm attempting to write a simple python script that will calculate the squareroot of a numbe开发者_StackOverflowr. heres the code i've come up with and it works. but i would like to learn how to use fractional exponents instead.

var1 = input('Please enter number:')
var1 = int(var1)

var2 = var1**(.5)
print(var2)

thanks for the help

You can use fractional exponents with the help of fractions module.

In this module there is a class Fraction which works similar to our inbuilt int class.
Here is a link to the documentation of the class - http://docs.python.org/library/fractions.html (just go through its first few examples to understand how it works. It is very simple.)

Heres the code that worked for me -

from fractions import Fraction  
var1 = input('Please enter number:')  
var1 = Fraction(var1)  
expo = Fraction('1/2')           //put your fractional exponent here  
var2 = var1**expo  
print var2

numerator, denominator = [float(s) for s in raw_input().strip().split("/")]
print 2 ** (numerator/denominator)

I strip whitespace from the input, split it into parts, then convert the parts to numbers with a list comprehension.

This will fail if the input isn't in fractional form. To check and behave appropriately...

line = raw_input().strip()
if "/" in line:
    numerator, denominator = [float(s) for s in line.split("/")]
    exponent = numerator/denominator
else:
    exponent = float(line)

print 2 ** exponent

If you had tried using 2 ** (1/2) and it had failed, that is because 1 and 2 are integers, so Python 2 uses integer division and ignores the fractional part. You could fix this by typing 1.0/2 into your script or input().