Vale Library Test | Python Fiddle

def main():
    lib = {} ### THIS IS WHERE lib IS DECLARED/DEFINED

book1 = {'name':'Alice','author':'Lewis'}
    book2 = {'name':'Rainbow','author':'Clancy'}

lib['ID1'] = book1
    lib['ID2'] = book2

passInteger = 0
    
    ############# START FOR LOOP ################
    for libKey in lib:  ### <---- THIS IS WHERE libKey is defined each time the loop runs
        passInteger = passInteger + 1
        passString = str(passInteger)
        
        print("///////// Pass " + passString + " //////////")
        
        print("This variable is the libkey, it changes every pass:")
        print(libKey)
        print("")
        
        print("This is the libKey put into the lib to return a specific book:")
        print(lib[libKey])
        print("")
        
        print("This is the entire library, it " +
              "shouldn't change with any pass because " +
              "the only variable that changes with each pass " +
              "is libKey and that's not used here:")
        print(lib)
        print("")
        print("")
        
        print("///////// END PASS" + passString + "/////////")
        print("")
    ############ END FOR LOOP ###############
    
    print('do you understand why each print command printed what it printed?')

main()

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