Valider un RIB en python

valid-RIB.py

def validRIB(banque, guichet, compte, cle):
    # http://fr.wikipedia.org/wiki/Clé_RIB#V.C3.A9rifier_un_RIB_avec_une_formule_Excel
    import string
    lettres = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    chiffres = "12345678912345678923456789"
    # subst letters if needed
    for char in compte:
        if char in string.letters:
            achar = char.upper()
            achiffre = chiffres[lettres.find(achar)]
            compte = compte.replace(char, achiffre)
    reste = ( 89*int(banque) + 15*int(guichet) + 3*int(compte) ) % 97
    ccle = 97 - reste
    return (ccle == int(cle))

here is a little update using string.ascii_letters

# all params as string
def validRIB(banque, guichet, compte, cle):
    # http://fr.wikipedia.org/wiki/Clé_RIB#V.C3.A9rifier_un_RIB_avec_une_formule_Excel
    import string
    lettres = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    chiffres = "12345678912345678923456789"
    # subst letters if needed
    for char in compte:
        if char in string.ascii_letters:
            achar = char.upper()
            achiffre = chiffres[lettres.find(achar)]
            compte = compte.replace(char, achiffre)
    reste = ( 89*int(banque) + 15*int(guichet) + 3*int(compte) ) % 97
    ccle = 97 - reste
    print((ccle == int(cle)))

is there an example how to run this function
where do i get
bank ...... key
what if i have just an IBAN

https://www.iban.fr/exemple.html

IBAN = "FR7630001007941234567890185" # taken for website above
CP = IBAN[0:2]
CC = IBAN[2:4]
BANQUE = IBAN[4:9]
GUICHET = IBAN[9:14]
COMPTE = IBAN[14:25]
CLE = IBAN[25:27]
# print(CP, CC, BANQUE, GUICHET, COMPTE, CLE)
validRIB(BANQUE, GUICHET, COMPTE, CLE)