
    Design a function for an automated writing assessment system that identifies the first unique character in a student's submitted text, helping detect distinctive writing patterns or potential typing errors. The function should analyze the text and return the first character that appears exactly once in the submission.
    

    
def first_non_repeating_character(str1):
    """
    Design a function for an automated writing assessment system that identifies the first unique character in a student's submitted text, helping detect distinctive writing patterns or potential typing errors. The function should analyze the text and return the first character that appears exactly once in the submission.
    

    """
def first_non_repeating_character(str1):
    """
    Design a function for an automated writing assessment system that identifies the first unique character in a student's submitted text, helping detect distinctive writing patterns or potential typing errors. The function should analyze the text and return the first character that appears exactly once in the submission.
    

    """
    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