def split_string(source,splitlist):
    ## Variables ##
    output = []
    start, start_pos, tracker = 0 , 0 , 0
    end_pos = 0

    ## Iterations ##
    for char in source:
        start = source.find(char,start)
        if char in splitlist:
            tracker += 1
            if tracker <= 1:
                end_pos = source.find(char, start)
                output.append(source[start_pos:end_pos])
                start_pos = end_pos + 1
            else:
                start_pos+=1
        else:
            tracker = 0
            
    output.append(source[end_pos+1:])

    return output



out = split_string("First Name,Last Name,Street Address,City,State,Zip Code,",",")
print out