Add ability to pass a list of show commands

There are frequently questions asked in online forums of how best to send a list of separate show type commands to a device with Netmiko. Today there are two methods:

1. Utilize send_config_set(), which is less than ideal, because of two reasons. First, it requires the user to have write access to the device, and second it will attempt to issue the commands in the configuration mode which potentially will not function depending on the network device vendor/platform.
2. Utilize a looping construct in Python to iterate over the list of commands and issue individual send_command() and return the output. While this is commonly used, having every user of Netmiko re-invent the wheel is less than optimal.

Ideally, there would be another method such as send_command_list(), that accepted a sequence of Str and issued the commands itself. It would then return a Dict with the command string as the key, and the output of those commands in strings as the value.

I have implemented something similar to this here: https://github.com/lykinsbd/naas/blob/master/naas/library/netmiko_lib.py#L24

While not directly applicable for upstreaming, the general idea is there and can form the basis of a send_command_list() method. I can look at creating a PR for this later this week.

[ktbyers]

I am warming a bit to the idea of building a method send_command_list

Take expect_list as an argument. Support all of the other arguments of send_command besides expect_string (i.e. this would have to come from expect_list).

Return a dictionary of results:

key —> the command set value —> the send_command response corresponding to that key.

[daanvdsanden]

Ideally, there would be another method such as send_command_list(), that accepted a sequence of Str and issued the commands itself. It would then return a Dict with the command string as the key, and the output of those commands in strings as the value.

It would be great if the dict values are the result of the send_command function. So the TextFSM integration is still there. And these parameters are passable to the function.