Export Symbols

export.py

import os

from PyQt4.QtCore import *
from PyQt4.QtGui import *

outdir = '~/temp/'
size = QSize(32, 32)

def get_gen(name):
    gen = QSvgGenerator()
    filename = os.path.join(outdir, name + ".svg")
    gen.setFileName(filename)
    gen.setSize(size)
    gen.setViewBox(QRect(0,0,size.width(),size.height()))
    return gen

layers = QgsMapLayerRegistry.instance().mapLayers().values()
for layer in layers:
    if not layer.type() == QgsMapLayer.VectorLayer:
       continue
    
    renderer = layer.rendererV2()
    items = renderer.legendSymbolItemsV2()
    for item in items:
        name = item.label()
        symbol = item.symbol()
        gen = get_gen(name)
        painter = QPainter(gen)
        symbol.drawPreviewIcon(painter, size)
        painter.end()
        print "Exported" + gen.fileName()

Had to import QtSvg to work for me.

from PyQt4.QtSvg import *