处理txt文件, 如果第一列和第二列的值在连续的行中重复，则只保留一个实例，使用Python的内置函数来读取文件，并逐行检查和处理数据。

一个txt文件，里面的数据是893.554382324,-119.955825806,0.0299997832626,-0.133618548512,28.1155740884,112.876833236,46.7922,19.625824753
893.554382324,-119.955825806,0.0299997832626,-0.133618548512,28.1155761706,112.876834056,46.788,19.612338826
893.554382324,-119.955825806,0.0299997832626,-0.133618548512,28.1155781986,112.876834852,46.7825,19.598998425
893.554382324,-119.955825806,0.0299997832626,-0.133618548512,28.1155804657,112.876835732,46.7808,19.567675623
893.554382324,-119.955825806,0.0299997832626,-0.133618548512,28.1155826663,112.87683659,46.7819,19.534835496
893.554382324,-119.955825806,0.0299997832626,-0.133618548512,28.1155851194,112.876837565,46.7761,19.508004894
894.695861816,-120.11151123,0.0300521384925,-0.130729228258,28.1155876674,112.876838582,46.759,19.476558928
894.695861816,-120.11151123,0.0300521384925,-0.13072