# Message from Python discussions

December 2018

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`list_1 = [1, 2, 3, 4, 5, 6]list_2 = []for ...     your magic here, append elements to list_2`

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`HAO = (Open of previous bar + Close of previous bar) / 2HAC = (Open + High + Low + Close) / 4HAH = Highest of High, Open, or CloseHAL = Lowest of Low, Open, or Close`

— So i have a list with each Open, High, Low, Close

— And i try to do this:

`for x in opens:        hsopens+=[(opens[-2]+closes[-2])/2]`

— But my approach is not correct, i am trying to figure out how to solve this formula

— So i have the list of opens for example that is:
[232,12435,343,12312,5545]
and closes that is:
[9343,5452,2341,6767]
For example, and i want to deploy this formula

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— HAO

— I tought at first that opens[-2] would do the trick but i need to do it recursively trough all the list

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— So i think i need an aditional forloop

— Use simple list comprehension

— Much easier to read and write

— Yes i've found solution using forloop