获取二维列表中的正确值

value = matrix[1][2]  # 获取第二行第三列的值，即6

target_value = 5
for row in matrix:
    for element in row:
        if element == target_value:
            print(f"找到值 {target_value} 在位置 {matrix.index(row)}, {row.index(element)}")

values_greater_than_4 = [element for row in matrix for element in row if element > 4]
print(values_greater_than_4)  # 输出: [5, 6, 7, 8, 9]

try:
    value = matrix[3][3]  # 这将引发错误，因为最大索引是[2][2]
except IndexError as e:
    print(f"索引越界: {e}")

if 0 <= row_index < len(matrix) and 0 <= col_index < len(matrix[0]):
    value = matrix[row_index][col_index]

irregular_matrix = [
    [1, 2],
    [],
    [3, 4, 5]
]

for row in irregular_matrix:
    if row:  # 检查行非空
        for element in row:
            print(element)