fix: shortcut error in loop

[weiduhuo]

What is the problem that this PR addresses?

When we use the select method within a loop, and the Choice parameter sequence is defined outside the loop, shortcut keys in alternating loops are presented in a doubled manner of the actual values.

example:

import questionary
from questionary import Choice

options = [Choice("One"), Choice("Two"), Choice("Three")]
for _ in range(4):
    option = questionary.select("Title:", options, use_shortcuts=True).ask()

How did you solve it?

The root cause is that, during the initialization of the InquirerControl.choices in the _init_choices process, when a Choice object is instantiated with another Choice object as a parameter, it directly references and passes the return result. This causes the shortcut_key parameter state of the Choice object to be retained in the loop, leading to the aforementioned issue.
We can resolve this issue by modifying the build method of the Choice class. When accepting a Choice-type parameter, we can return the result using a shallow copy."

import copy

if isinstance(c, Choice):
   return copy.copy(c)

Checklist

• I have read the Contributor's Guide.
• I will check that all automated PR checks pass before the PR gets reviewed.

[kiancross]

Thanks for spotting this bug and submitting a PR. From what I understand, the problem is as follows:

1. When a Choice is instantiated without a shortcut, Choice.shortcut_key is None and so Choice.auto_shortcut is set to True.
2. Choices passed to InquirerControl are untouched if they are an instance of a Choice (and so any changes made to the choice by InquirerControl are preserved across calls).
3. _assign_shortcut_keys iterates through choices and removes shortcuts which have already been assigned from the list.
4. Remaining shortcuts are then assigned to choices with auto_shortcut set to True.

The problem occurs on subsequent calls to (3) and (4).

I see a few possible solutions:

1. The one you have proposed.
2. Once Choice.shortcut_key is set, Choice.auto_shortcut should be set to False. So the following logic should be moved into a setter for Choice.shortcut_key:
   

   questionary/questionary/prompts/common.py

   Lines 93 to 102 in 1c66330

   	if shortcut_key is not None:
   	if isinstance(shortcut_key, bool):
   	self.auto_shortcut = shortcut_key
   	self.shortcut_key = None
   	else:
   	self.shortcut_key = str(shortcut_key)
   	self.auto_shortcut = False
   	else:
   	self.shortcut_key = None
   	self.auto_shortcut = True

3. Either adding and not c.auto_shortcut here:

   questionary/questionary/prompts/common.py

   Line 292 in 1c66330

   if c.shortcut_key is not None:

   
   or c.shortcut_key is not None here:
   

   questionary/questionary/prompts/common.py

   Line 306 in 1c66330

   if c.auto_shortcut and not c.disabled:

What do you think?