How to use abbrevs

I find using abbrevs in Emacs confusing. Despite reading the manual and the EmacsWiki, I continue to have problems using them.

Goal:

Define a quick, throw-away abbrev for a single Emacs session.

Example:

When using Python and Numpy, outputs are sometimes shortened with an ellipsis:

array(['1007.65', '1007.63', '1007.66', ..., '993.40', '993.40', '993.57'], dtype=object) 

To display the array in full, you need to issue this mouthful of a statement:

with np.printoptions(threshold=np.inf): print(my_arr['field_name']) 

This seems like a perfect situation for an abbrev!

Here's what I do:

1. Type fp for "full print"
2. With point immediately after p in fp, issue C-x a g (add-global-abbrev)
3. In the minibuffer prompt for Global abbrev for "fp":, put with np.printoptions(threshold=np.inf): print() and press <RET>
4. The minibuffer exits, returning me to my original buffer with point after p in fp
5. Issue C-x a e (expand-abbrev)

Nothing happens.

If I check list-abbrevs, there it is:

(global-abbrev-table) "with np.printoptions(threshold=np.inf): print()" 0 "fp" 

My understanding is that I don't need abbrev-mode enabled, as that's only used for automatic expansion. Incidentally, enabling abbrev-mode still doesn't expand fp.

I'm at a loss for what I'm doing wrong and would appreciate some advice!