
    In a delivery fleet management system, develop a function that analyzes a vehicle's route code to identify the first unique route segment identifier (represented by a single character) that appears exactly once in the code. This identifier will be used to determine the primary unique delivery zone for the vehicle's current route.
    

    
def first_non_repeating_character(str1):
    """
    In a delivery fleet management system, develop a function that analyzes a vehicle's route code to identify the first unique route segment identifier (represented by a single character) that appears exactly once in the code. This identifier will be used to determine the primary unique delivery zone for the vehicle's current route.
    

    """
def first_non_repeating_character(str1):
    """
    In a delivery fleet management system, develop a function that analyzes a vehicle's route code to identify the first unique route segment identifier (represented by a single character) that appears exactly once in the code. This identifier will be used to determine the primary unique delivery zone for the vehicle's current route.
    

    """
    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