# average3.py def main(): sum = 0.0 count = 0 x = eval(input("Enter a number (negative to quit) >> ")) while x >= 0: sum = sum + x count = count + 1 x = eval(input("Enter a number (negative to quit) >> ")) print(" The average of the numbers is", sum / count) main()

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# average4.py def main(): sum = 0.0 count = 0 xStr = input("Enter a number ( to quit) >> ") while xStr != "": x = eval(xStr) sum = sum + x count = count + 1 xStr = input("Enter a number ( to quit) >> ") print(" The average of the numbers is", sum / count) main()

Test files average3.py, average4.py

With a single .txt file, revise files with line-by-line explanation. (Using # to add comment/explanation)

One file with line-by-line explanation, followed by one running result with IDLE shell information (try to use the same testing inputs to see the differences between each .py files).