How to pretend in a simple way

Here is title

The text begins, I'm almost starting to get excited

cough cough...

#Verification code 
import random 
yan = "" 
for i in range(0,4): 
    cun=random.randrange(1,4) 
    if cun==i: 
        tmp=chr(random.randint(65,90)) 
    else: 
        tmp=random.randrange(0,9) 
    yan+=str(tmp) 
print(yan) 
var=input("Please enter the verification code:") 
if var == yan: 
    print('Success') 
else: 
    print("Failed ") 
This simply implements a verification code function with python3