
    Write a function that identifies the first unique character in a patient's identification code to validate its compliance with the hospital's non-duplicate ID policy. The function should process the alphanumeric ID string and return the first character that appears exactly once, helping maintain the integrity of patient records in the electronic health system.
    

    
def first_non_repeating_character(str1):
    """
    Write a function that identifies the first unique character in a patient's identification code to validate its compliance with the hospital's non-duplicate ID policy. The function should process the alphanumeric ID string and return the first character that appears exactly once, helping maintain the integrity of patient records in the electronic health system.
    

    """
def first_non_repeating_character(str1):
    """
    Write a function that identifies the first unique character in a patient's identification code to validate its compliance with the hospital's non-duplicate ID policy. The function should process the alphanumeric ID string and return the first character that appears exactly once, helping maintain the integrity of patient records in the electronic health system.
    

    """
    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