A chess library, where the only purpose is to convert a PGN structur to FEN.

The lib exposes several methods, to be used.

You can insert one and one move if you want.

import pgntofen # assumes you have pgntofen.py in the same directory, or you know how to handle python modules.
pgnConverter = pgntofen.PgnToFen()
pgnConverter.move('d4')
fen = pgnConverter.getFullFen()
#fen will be 'rnbqkbnr/pppppppp/8/8/3P4/8/PPP1PPPP/RNBQKBNR b - KQkq'

You can send a string, or an array of strings. If you send a string, it may be a valid PGN Line (1.e4 d5 2.Nf3 ....) if it'a and array of strings, you may only send the actulle moves (['e4', 'd5', 'Nf3'])

import pgntofen # assumes you have pgntofen.py in the same directory, or you know how to handle python modules.
pgnConverter = pgntofen.PgnToFen()
PGNMoves = 'd4 d5'
pgnConverter.pgnToFen(PGNMoves.split(''))
fen = pgnConverter.getFullFen()
#fen will be 'rnbqkbnr/ppp1pppp/8/3p4/3P4/8/PPP1PPPP/RNBQKBNR - KQkq'

parse a pgnFile that may have sveral pgn games. See test/Carlsen.pgn for an example

pgnConverter = pgntofen.PgnToFen()
pgnConverter.resetBoard()
file = "test/Carlsen.pgn"
stats =  pgnConverter.pgnFile(file);
# stats => {
# 'failed': [<pgntofen-error-obj>, ...],
# 'succeeded': [<game-obj>, ...]
# }

# a game-obj: (game_info, fens)
# pgntofen-error-obj: (game_info, lastMove, fen, error)
# fens: array of fen
# game_info is all the line in the pgn file working as a header before the game (e.g: all lines with [...])

Running 20 000 games with pgntofen takes about 45-50 seconds on a normal laptop (4GB Ram, i7, SSD). With chess-python this takes about 6m 15s to 6m 30s. So you should expect an 8x improvement at least.

The file fenStats.py takes either "pgntofen" or "chess-python" as input. to test on your computer run time python fenStats.py pgntofen and time python fenStats.py chess-python.

To run the test on each change, you can start the watch.sh script. ./watch.sh pwd pgntofen.test.py will run the test script pgntofen.test.py on each save to the current dir.

The python-chess lib is and excellent library. If something goes wrong with this library, see if you can run the same moves with chess-python. If there is a mistake there also, it's probably something wrong with the moves you are putting in.