解释**如果__name__ =='__main __'**：在下面的代码中指示

Question

import sys

def main() :
    f = open(r'C:\Users\avinpandey\Desktop\SRC_SAMPLE_BP_CRETAE_POSTLOAD.txt',mode = 'rt', encoding='utf-8')
    for line in f :
        sys.stdout.write(line)
    f.close()

if __name__ == '__main__':
    main()