
    Write a function that identifies the first unique character in a loan application's transaction ID string to ensure no duplicate applications are processed in the credit risk assessment system. The function should scan through the transaction ID and return the first character that appears exactly once, helping maintain the integrity of loan processing records.
    

    
def first_non_repeating_character(str1):
    """
    Write a function that identifies the first unique character in a loan application's transaction ID string to ensure no duplicate applications are processed in the credit risk assessment system. The function should scan through the transaction ID and return the first character that appears exactly once, helping maintain the integrity of loan processing records.
    

    """
def first_non_repeating_character(str1):
    """
    Write a function that identifies the first unique character in a loan application's transaction ID string to ensure no duplicate applications are processed in the credit risk assessment system. The function should scan through the transaction ID and return the first character that appears exactly once, helping maintain the integrity of loan processing records.
    

    """
    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