Update README.md

README.md

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 Project to display the funds required to support a repeated expense indefinitely. The primary purpose of the expense_impact.py script is to get folks thinking about the total cost of personal expenses. 'Annuitized' expenses often appear supportable when their total 'cost of ownership' is actually remarkably high. For example, how much money would you need to save to support a daily $3.50 coffee habit in retirement - it turns out that addiction requires a lot of $! The secondary purpose is to get some repetitions messing around in python & running a script. There are several embedded "goodies" in the expense_impact.py script - opportunities for improvement.
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 Potential solutions for the "goodies" are demonstrated in expense_impact-solution.py in case you would like a frame of reference or comparison. It is also a cleaner, more capable solution if you want to consider different retirement ages, Safe Withdrawal Rates, etc.
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+Requires python 3.6 or later