Can anyone explain this pseudocode to find a returning address?

Can anyone explain this pseudocode to find a returning address?

I was reading a popular answer which explains how to find the address of the person who sent a transaction and the pseudocode in that answer does not make much sense to me.

txid = <relevant transaction id>
addresses = []
raw_tx = decoderawtransaction(getrawtransaction(txid))
for(input in raw_tx['vin']) {
  input_raw_tx = decoderawtransaction(getrawtransaction(input['txid']))
  addresses.push(input_raw_tx['vout'][input['vout']]['scriptPubKey']['addresses'][0])
}

Here is the part which I understood. A wallet which created txid can use many inputs from different addresses to send that amount of money. This is why we iterate over input in raw_tx['vin'] and create a list of addresses addresses = [].

Here is a part which is unclear for me:

input_raw_tx['vout'][input['vout']]['scriptPubKey']['addresses'][0]

input_raw_tx['vout'] returns the list. So input['vout'] should return the index of that list. But it also returns a list. Can anyone explain what is going on?

Also that answer was written in old 2013. Has anything changed in these 4 years and is there an easier way to find the returning address as of the beginning of 2918?

http://ift.tt/2C9UnLP