Base X string encoding

Question

I'm looking for a routine that will encode a string (stream of bytes) into an arbitrary base/alphabet (like base64 encoding but I get to choose the alphabet). I've seen a few routines that do base X encoding for a number, but not for a string.

Answer 1

Every algorithm I've seen (and written) for this has a sequence of characters, and does a divmod of the number by the length of the sequence, uses the mod for the index into the sequence for the digit character, and feeds the div back into the process.