
    In a banking system processing loan applications, write a function that identifies the first unique character in a customer's application reference code to help generate a distinct tracking identifier. The system needs to analyze the reference code string and return the first character that appears exactly once to ensure reliable application tracking and prevent duplicate processing.
    

    
def first_non_repeating_character(str1):
    """
    In a banking system processing loan applications, write a function that identifies the first unique character in a customer's application reference code to help generate a distinct tracking identifier. The system needs to analyze the reference code string and return the first character that appears exactly once to ensure reliable application tracking and prevent duplicate processing.
    

    """
def first_non_repeating_character(str1):
    """
    In a banking system processing loan applications, write a function that identifies the first unique character in a customer's application reference code to help generate a distinct tracking identifier. The system needs to analyze the reference code string and return the first character that appears exactly once to ensure reliable application tracking and prevent duplicate processing.
    

    """
    char_order = []
    ctr = {}
    for c in str1:
        if c in ctr:
            ctr[c] += 1
        else:
            ctr[c] = 1
            char_order.append(c)
    for c in char_order:
        if ctr[c] == 1:
            return c
    return None