there are some problems in the code：del stats, iters_train, ld_train, visualizer

[rank1]:   File "/home/chenjr/Infinity/train.py", line 424, in main_train
[rank1]:     del stats, iters_train, ld_train, visualizer
[rank1]: UnboundLocalError: local variable 'visualizer' referenced before assignment
这里的visualizer还未定义就被使用了