
    In a real-time fraud detection system, develop a function that identifies the first unique security flag within a transaction identifier string, where each character represents different security markers. The first non-repeating character in the identifier helps pinpoint specific transaction anomalies that require immediate attention from the fraud detection team.
    

    
def first_non_repeating_character(str1):
    """
    In a real-time fraud detection system, develop a function that identifies the first unique security flag within a transaction identifier string, where each character represents different security markers. The first non-repeating character in the identifier helps pinpoint specific transaction anomalies that require immediate attention from the fraud detection team.
    

    """
def first_non_repeating_character(str1):
    """
    In a real-time fraud detection system, develop a function that identifies the first unique security flag within a transaction identifier string, where each character represents different security markers. The first non-repeating character in the identifier helps pinpoint specific transaction anomalies that require immediate attention from the fraud detection team.
    

    """
    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