down vote
	

Beside that I don't understand your problem with PyWaller, like Eyal suggests, you can use the standard Bitcoin software for this as well, although this method will be a little more time-consuming.

I suggest doing the following for every wallet.dat file you have:

    Backup your current wallet.dat file.
    Copy the old wallet.dat to your Bitcoin directory.

    Open up a terminal and run the bitcoind daemon:

    bitcoind -daemon

    Retrieve a list of all the addresses in the wallet:

    bitcoind listaddressgroupings

    For every address you want the private key from, dump it:

    bitcoind dumpprivkey <bitcoinaddress>

    Stop the daemon before changing the wallet.dat file:

    bitcoind stop