Find the first non-repeated character in a string

Question

I read of a job interview question to write some code for the following:

Write an efficient function to find the first nonrepeated character in a st

Answer 1

The following code traverses through the string only once. It's a simple and easy solution for the problem but at the same time the space complexity is compromised.

def firstNonRepeating(a):
    inarr = []
    outarr = []

    for i in a:
        #print i
        if not i in inarr:
            inarr.append(i)
            outarr.append(i)
        elif i in outarr:
            outarr.remove(i)
        else:
            continue
    return outarr[0]

a = firstNonRepeating(“Your String”)
print a