Alpha-Range

As you know, the function range() returns a range of numbers, but it doesn't work on alphabets. In this challenge, we try to fill this gap.

Write a function alpha-range() which takes three arguments start, stop, and step (which its default value is one). The function must return a list of alphabetical characters, ranging from start character to stop character based on step value.

The function must follow these conditions:

• If step is zero or more than 26 or less than -26, return "step must be a non-zero value between -26 and 26, exclusive".

• Both start and stop must share the same case, otherwise, return "both start and stop must share the same case".

Like range() function:

• step must not be zero.

Unlike range() function:

• returned list must be inclusive.
• the order of characters doesn't affect the output (i.e. the output of alpha_range("a", "f") is the same as alpha_range("f", "a"), see examples).

Examples

alpha_range("a", "f") ➞ ["a", "b", "c", "d", "e", "f"]

alpha_range("f", "a") ➞ ["a", "b", "c", "d", "e", "f"]

alpha_range("a", "f", -1) ➞ ["f", "e", "d", "c", "b", "a"]

alpha_range("f", "a", -1) ➞ ["f", "e", "d", "c", "b", "a"]

alpha_range("A", "F", -1) ➞ ["F", "E", "D", "C", "B", "A"]

alpha_range("A", "F", 0) ➞ "step must be a non-zero value between -26 and 26, exclusive"

alpha_range("A", "F", -26) ➞ "step must be a non-zero value between -26 and 26, exclusive"

alpha_range("a", "F", -1) ➞ "both start and stop must share the same case"

Notes

All the start and stop values in the tests are valid alphabetical characters.