DESCRIPTION gevent module function and application scenarios.

When a greenlet encountered IO operations, such as access to the network, it automatically switches to the other greenlet, IO wait until the operation is completed,

And then at the appropriate time to switch back to continue. Since the IO operation is very time-consuming, often make the program in a wait state,

With gevent for our automatic switching coroutine, ensures that there is always greenlet running, instead of waiting for IO.
Since the switching is done automatically in the IO operation, it comes with Python gevent need to modify some standard libraries,

This process is completed at startup by monkey patch: