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

input_str = "interesting"
#input_str = "aabbcc"
#input_str = "aaaapaabbcccq"


def firstNonRepeating(param):
    counts = {}        
    for i in range(0, len(param)):

    # Store count and index repectively
        if param[i] in counts:
            counts[param[i]][0] += 1
        else:
            counts[param[i]] = [1, i]

    result_index = len(param) - 1
    for x in counts:
        if counts[x][0] == 1 and result_index > counts[x][1]:
            result_index = counts[x][1]
    return result_index

result_index = firstNonRepeating(input_str)
if result_index == len(input_str)-1:
    print("no such character found")
else:
    print("first non repeating charater found: " + input_str[result_index])