I need help please. Our teacher said he will give is a similar code to this one in the exam. But he will do some changes in the second line. Can anyone give me some exemples? Because I don't know how to revise



1ch=input("Donner une chaine numérique à 4 chiffres:")
2 while not (ch.isdecimal() and len(ch)==4):
3 ch=input("Re-donner une chaine numérique à 4 chiffres:")
X=""
for i in range(len(ch)):
crypte= (int(ch[i])+5) % 10
x=x+ str(crypte)
10print("le code ", ch, " est crypté ",x)
11 print(crypte)​