我试图打印序列，但得到KeyError？在python中

I am getting only first input file correct output but I have A , B, C, D chain in my first file and getting right output, in this case in second input file does't have c and d chain in this case, our code is copying same data of first file data of C and D.? and also I am unable to increase this ids: chainIDs = ['A', 'B', 'C', 'D']I am getting only first input file correct outp