terminals = set()是什么意思

这行代码创建了一个空的集合（set）对象，命名为terminals。集合是Python中的一种无序、可变、不重复的数据结构，可以用于存储一组互不相同的元素。在这里，我们可以把terminals看作是一组终止符号（terminals），用于编写语法分析器等程序中的符号表。可以通过添加或删除元素来修改集合的内容。

相关问题

gdb failed to set controlling

terminal: Operation not permitted

This error message indicates that the gdb debugger was not able to set the controlling terminal for the process being debugged. This can happen if the process is running with elevated privileges or if there are restrictions on the controlling terminal in the system.

To resolve this issue, try running gdb with elevated privileges (as root or with sudo) or try using a different terminal. You can also check if there are any system restrictions on controlling terminals and adjust them accordingly.

GNUPLOT No output will be generated. Please select a terminal with 'set terminal'.

It seems that you are facing an issue with GNUPLOT where no output is being generated. To resolve this, you need to select a terminal using the 'set terminal' command. GNUPLOT supports various output terminals such as X11, PNG, PDF, and more.

For example, if you want to generate output on the X11 terminal, you can use the following command:

set terminal x11

If you prefer PNG output, you can use:

set terminal png

You can also specify additional options for the terminal, such as the output file name or resolution. Once you have selected the desired terminal, you should be able to generate the output successfully.

Please note that the exact commands and options may vary depending on your specific use case and GNUPLOT version. Make sure to consult the GNUPLOT documentation or refer to relevant online resources for more detailed information.