This is a simple script used to generate alpha revision sequences.
The initial release is specified as the number 0, with subsequent revisions
specified by upper case letters.
When revising revision Z, the next revision is AA. This will create the
following sequence.
0, A, B, C, ..., X, Y, Z, AA, AB, AC, ..., AX, AY, AZ, BA, BB, BC, ...
The default sequence is the whole alphabet
This can be modified by passing "partial" to remove letters I, O,
and S to avoid confusing them with numbers 1, 0, and 5.
The disadvantage of using "partial", is that there are fewer revisions that
can be made compared to "full".
# "full"
# length: 26
# number of revisions: 26 + 26**2 = 702 + initial release
sequence = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
# "partial":
# length: 23 (alphabet without i, o, and s)
# number of revision: 23 + 23**2 = 552 + initial release
sequence = "ABCDEFGHJKLMNPQRTUVWXYZ"
If the parameter passed to revision is not either "full" or "partial",
a ValueError is raised.
When the number of revisions runs out, a MaximumRevisionError is raised,
signaling the end of the revision sequence.