nft.py

import hashlib

def hash_image(filename,BUFFER_SIZE=4096):
   hash_function = hashlib.sha512()
   with open(filename,'rb') as file:
       data=True
       while data:
       	   data = file.read(BUFFER_SIZE)
       	   if not data:
       	   	break
           hash_function.update(data)      
   return hash_function.hexdigest()



def get_marketplace(blochchain):
    ItemList=[]
    Items=[]
    NotForSale=[]
    print("Items for sale listed below:")
    for block in reversed(blochchain):

        if block.for_sale and block not in NotForSale:
            ItemList.append({"Seller" : block.buyer, "Token" : block.token})
            print("**************************")
            print("Seller: ", block.buyer)
            print("Token: ", block.token)
            print("**************************")
            print ("")
            Items.append(block)
        elif block.for_sale and block not in Items and block not in NotForSale:
            NotForSale.append(block)
    if len(ItemList) ==0:
        print("Empty market")
    
    return ItemList