Create constants for offsets into a list

I have a list similar to this:

host_info = ['stackoverflow.com', '213.213.214.213', 'comments', 'desriprion', 'age']

Sometimes, I need to remove one or more elements from the list and then return the list to the caller开发者_运维百科. To remove the comments item as an example I'd do this:

host_info.pop(2)

I'd prefer to use a constant for each item rather than some magic number.

Then I could use:

host_info.pop(comments) # comments is integer 2

What's the best way to enumerate these constants so it's simple to maintain them when the list offsets change?

The easiest approach would be to change your list to a dictionary:

 keys_list = ['host',...]
 host_info = dict(zip(['stackoverflow.com', '213.213.214.213', 'comments', 'desriprion', 'age'], keys_list))

Now you don't have to worry about the key list and if you remove an item from the host_info dictionary it won't affect the key => value associations

or if you only have one host info list:

host_info = {'host':'stackoverflow.com, 'ip':'213.213.214.213',...}

EDIT:

To remove a key from the host_info use pop:

host_info.pop('host')

If you aren't sure the key is there you can use:

host_info.pop('host',None)

or you can use:

if 'host' in host_info:
    del host_info['host']

As a side note AdamKG has a nice comment explaining that you wouldn't want to convert this back to a list. You could instead do this:

 host = host_info['host']

This removes the dependence on a "key" mapping list and combines the two lists into a single associative container.