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python/10-reverse-polish-notation/README.md

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+Reverse Polish Notation
+=======================
+
+You've never done it until you've done it reverse polish.
+
+I don't know what that means, but check this out on [reverse polish notation](http://en.wikipedia.org/wiki/Reverse_Polish_notation).
+
+Reverse polish notation is a mathematical notation in which every operator follows all of its operands. For example:
+
+	3 4 + >>> 7  
+	4 2 / >>> 2  
+	10 7 2 - * 5 / >>> 10
+
+Write a program that accepts a RPN equation as a command line argument, such that you would execute your program:
+
+		python3 rpn_calc.py 10 9 - 5 +
+
+Which would then return you 6, the result of that equation.
+
+###ARGV
+
+To run the program like this you need to import the sys library and access sys.argv. 
+
+ARGV gives us the arguments used to launch the program as an array. The first position is always the application name / file. The next are all others divided by spaces.
+
+Read about sys.argv [here](http://www.pythonforbeginners.com/system/python-sys-argv)
+
+Sandbox with this so you know what you are getting as an input.
+
+Here's a nice hint - we can "slice" arrays in Python like in JS just by doing:
+
+		array = ['hi', 'wut', 'm8', 'lol', 'doge']
+		array[2:4] ### returns ['m8', 'lol']
+
+###Testing
+
+Write some assert statements after you've solved the challenge.
+
+NOTE: You might need to escape the multiplication operator * when you pass it in.