text: # ==BEGIN LICENSE==
  # 
  # MIT License
  # 
  # Copyright (c) 2018 SRI Lab, ETH Zurich
  # 
  # Permission is hereby granted, free of charge, to any person obtaining a copy
  # of this software and associated documentation files (the "Software"), to deal
  # in the Software without restriction, including without limitation the rights
  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  # copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  # 
  # The above copyright notice and this permission notice shall be included in all
  # copies or substantial portions of the Software.
  # 
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  # SOFTWARE.
  # 
  # ==END LICENSE==
  
  
  import re
  
  from dpfinder.psi.runPsi import run_on_string
  from dpfinder.scorer.scorer import Scorer
  from dpfinder.logging import logger
  from dpfinder.utils import evaluate_math as ev
  
  psi_flags = '--raw --mathematica --nonormalize'
  
  regex = re.compile(r"\*DiracDelta\[[^\]]*\]")
  
  
  class PSIScorer(Scorer):
  
  	def __init__(self, alg):
  		super().__init__()
  		self.alg = alg
  
  	def get_prob(self, a, o):
  		psi_script = self.alg.get_psi_script(a, o)
  		logger.debug(psi_script)
  		res = run_on_string(psi_script, psi_flags)
  		logger.debug("PSI time:%s", res.time)
  		logger.data('psi-time', res.time)
  		if res.error is not "":
  			logger.error("PSI error:" + res.error)
  			raise Exception("PSI error:" + res.error)
  		logger.debug("PSI output:%s", res.output)
  		if res.output == "DiracDelta[-r+1]":
  			ret = 1.0
  		else:
  			ret = regex.sub("", res.output)
  			logger.debug('Evaluating cleaned up expression: %s', ret)
  			ret = ev.eval_prob(ret)
  		logger.debug("PSI Scorer: Returning evaluated probability %s", ret)
  		return ret
  