如何用Python编写大文件

Question

我正在尝试从大文件中读取和处理每一行，然后将结果写入另一个文件。但是内存很快被用完了。还有其他好的解决方案请帮忙。

time_start = time.time()
tt_X = []
D_tmp = []
with open(filenameRead, 'r') as fr, open(fileNameWrite,'wa') as fw:
    for line in fr:
        _, _, D_tmp = line.strip().split(',') #      
        #process each line
        D_tmp = np.array( D_tmp.split() ).astype(int).reshape(15,4,101,101)/215.   
        #D_tmp = np.reshape(D_tmp, () )/215.
        for i in range(15):
            tt_X.append(D_tmp[i,1:4,:-1,:-1])
        encoded = encoder.predict(np.array(tt_X)).flatten()
        fw.writelines(' '.join(encoded.astype(str)) +'\n')
        tt_X = []
        D_tmp = []
time_end = time.time()
print 'The elapsed time is ', time_end - time_start