import sys import os '''     usage(1): merge_files pathname               pathname is directory and merge files in pathname directory     usage(2): merge_files file1 file2 [file3[...]] ''' FILE_SLIM = (256*(1024*1024)) #256M match 2**n def merge_files(fileslist,mfname):     global FILE_SLIM     p_fp = open(mfname,"wba")     for file in fileslist:         with open(file,"rb") as c_fp:             fsize = os.stat(file).st_size             count = fsize&FILE_SLIM             while count>0:                 p_fp.write(c_fp.read(FILE_SLIM))                 fsize -= FILE_SLIM                 count -= 1             p_fp.write(c_fp.read())     p_fp.close def main():     argc = len(sys.argv) - 1     fileslist = []     if argc == 2:         dir_name = os.path.realpath(sys.argv[1])         assert(os.path.isdir(dir_name))         file_dir = os.listdir(dir_name)         fileslist = [os.path.join(dir_name,file) for file in file_dir if os.path.isfile(os.path.join(dir_name,file))]         print(fileslist)     elif argc >=3:         fileslist = [os.path.realpath(sys.argv[index]) for index in range(1,argc) if os.path.isfile(os.path.realpath(sys.argv[index]))]     merge_files(fileslist,sys.argv[argc]) if __name__ == '__main__':     main()