PGN to FEN (with Evaluation)?

[Steve Maughan]

I'd like to convert a (large) PGN database to a FEN / EPD text file, with one FEN string for each position. And I'd like to append each move's comment / evaluation onto the end of each FEN string.

What's the easiest way to do this?

I've looked at SCID PC and PGN Extract and neither seem to do this. Is there any utility which will fit this purpose?

Thanks - Steve

P.S. Ideally I'd also like it to be able to handle FRC / Chess960 games as well

[Ferdy]

Could you post a sample game? let me see its format.

[elcabesa]

I think you could do it in 2 step.
First use pgn2epd to create the big list of fen position.
second write a little scripts that read a line, execute a small search with an engine and then record the result

i remember i did something like that in vajolet, but I didn't create the scritp, I modified vajolet to do the second step

[matthewlai]

I'd like to convert a (large) PGN database to a FEN / EPD text file, with one FEN string for each position. And I'd like to append each move's comment / evaluation onto the end of each FEN string.

What's the easiest way to do this?

I've looked at SCID PC and PGN Extract and neither seem to do this. Is there any utility which will fit this purpose?

Thanks - Steve

P.S. Ideally I'd also like it to be able to handle FRC / Chess960 games as well

If you know Python, the python-chess library should work. It would be something like 10 lines of code.

Actually, since I'm learning Python right now and need some practice, I can write it for you, in a few hours.

[matthewlai]

This should do it:

Code: Select all

#!/usr/bin/env python3

import chess
import sys

from chess import pgn

def PrintNode(gameNode):
	if len(gameNode.variations) > 0:
		print(gameNode.board().epd(sm = gameNode.variations[0].move, c0 = gameNode.variations[0].comment))
	else:
		print(gameNode.board().epd())

if len(sys.argv) != 2:
	print&#40;"Usage&#58; " + sys.argv&#91;0&#93; + " <PGN file>")
	sys.exit&#40;1&#41;

if sys.argv&#91;1&#93; == '-'&#58;
    pgn = sys.stdin
else&#58;
    pgn = open&#40;sys.argv&#91;1&#93;)

game = chess.pgn.read_game&#40;pgn&#41;
while game != None&#58;
	
	gameNode = game
	while len&#40;gameNode.variations&#41;&#58;
		PrintNode&#40;gameNode&#41;
		gameNode = gameNode.variations&#91;0&#93;
    
	# for the last node &#40;no variations&#41;
	PrintNode&#40;gameNode&#41;
        
	game = chess.pgn.read_game&#40;pgn&#41;

Code: Select all

sudo pip3 install python-chess
python3 pgn2epd.py input.pgn > output.epd

If you are processing very large files and performance matters, you'll probably want to grab the latest version of the python-chess library from github. I submitted a patch last week that makes it much faster.

[Steve Maughan]

HI Matthew,

Python Chess Library - it sounds fantastic! It may just be a good enough reason to dip my toe in the waters of Python.

Many thanks!

Steve

[Jesse Gersenson]

pgn-extract can convert a pgn to epd/fen. Here is the help file:
http://www.cs.kent.ac.uk/people/staff/d ... /help.html

Here's a start in bash:

Code: Select all

~$ pgn-extract -Wepd test.pgn |cut -d' ' -f1,2,3,4>tmp

Code: Select all

#!/bin/bash
while read p; do
motor=maverick
fen="position fen $p" 
echo $p
(echo "$fen";sleep 0.01;echo 'go depth 47'; sleep 1;echo 'quit';)|./$motor|grep "cp "|tail -1|sed 's/.*cp //g'|sed 's/ nps.*//g';
done <tmp

Outputs the fen and score in cp:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -
37
rnbqkbnr/pppppppp/8/8/8/5N2/PPPPPPPP/RNBQKB1R b KQkq -
-22
rnbqkbnr/pp1ppppp/8/2p5/8/5N2/PPPPPPPP/RNBQKB1R w KQkq c6
38
...