Allow lowercase characters in hex strings

[Adamtaranto]

The pattern given for tags of type H in the GFA 1.0 spec is [0-9A-F]+ which only allows uppercase characters.

I think lowercase characters are valid in hex strings so should the pattern be: [0-9A-Fa-f]+

Is the pattern wrong or should the hexstring be converted to uppercase?

import hashlib
import re

seq = "ATGC"

bytearray = hashlib.sha256(seq.encode()).digest()
# b'\x98 \xf5\xa8L\xc4\x043\x0em\x97\xbd\xe1;X\x0f\xe9\xbfh\xb9\xca\ttbE\x93\xf62ES\x08\x8c'

hex_string = bytearray.hex()
# '9820f5a84cc404330e6d97bde13b580fe9bf68b9ca0974624593f6324553088c'

re.fullmatch(r"[0-9A-F]+", hex_string)
# No matches

re.fullmatch(r"[0-9A-Fa-f]+", hex_string)
# <re.Match object; span=(0, 64), match='9820f5a84cc404330e6d97bde13b580fe9bf68b9ca0974624>