python - 从文件中读取行作为移位寄存器，在 Python 中有两个单元格

Question

我需要以这样的方式读取文件的行，这种方式将表现为具有两个单元格的移位寄存器。 例如:

with open("filename", 'r') as file:

 --first iteration--
 present = line1
 next  = line2
    do something

 --second iteration--
 present = line2
 next = line3
   do something

 --third iteration--
 present = line3
 next = line 4
    do someting

 and so on....

这可以通过 open(file, 'r') 完成，但它不能保证文件会被关闭，因为脚本可能会停止 由于在最后一次迭代之前“做某事”。

有什么优雅的方法吗？

Answer 1

当然:

with open("filename", 'r') as file:
    current_line = next(file)  # Get 1st line, advance iterator to 2nd line
    for next_line in file:
        do_something(current_line, next_line)
        current_line = next_line