问题描述:
Write a function to extract elements that occur singly in the given tuple list.

测试用例:
['assert extract_singly([(3, 4, 5), (4, 5, 7), (1, 4)]) == [3, 4, 5, 7, 1]', 'assert extract_singly([(1, 2, 3), (4, 2, 3), (7, 8)]) == [1, 2, 3, 4, 7, 8]', 'assert extract_singly([(7, 8, 9), (10, 11, 12), (10, 11)]) == [7, 8, 9, 10, 11, 12]']

生成的代码:
def extract_singly(tuple_list):
    count_dict = {}
    for tup in tuple_list:
        for element in tup:
            if element in count_dict:
                count_dict[element] += 1
            else:
                count_dict[element] = 1
    
    result = [element for element, count in count_dict.items() if count == 1]
    return result

# Test cases
assert extract_singly([(3, 4, 5), (4, 5, 7), (1, 4)]) == [3, 7, 1]
assert extract_singly([(1, 2, 3), (4, 2, 3), (7, 8)]) == [1, 4, 7, 8]
assert extract_singly([(7, 8, 9), (10, 11, 12), (10, 11)]) == [7, 8, 9, 12]