

book = {"chap1":10, "chap2":20 , "chap": 30,"chap1":100} 

print(book["chap1"])

##

book = {"chap1":10, "chap2":20 , "chap": 30} 

print(book["chap1"])


## adding key-value for the dictionary 


book["chap4"]= 40


print("updated dictionary :", book)

book["chap5"]= 50

print ("updated dictionary :", book)
