What is the {%d}
for in these regexp?
I've read: the re doc but I could not something about it (except maybe this part) .
B = r'( {%d})'
N = r'(\d{%d})'
NB = r'([0-9 ]{%d})'
A = r'(\w{%d})'
AB = r'([a-zA-Z ]{%d})'
AN = r'([a-zA-Z0-9]{%d})'
ANB = r'([a-zA-Z0-9 ]{%d})'
AMT = r'(\d{13}[{}A-R]{1})'
ALL = r'(.{%d})'