code: def _infer_ipa_col(self, header):
  		
  		if self.ipa_col and isinstance(self.ipa_col, str):
  			if self.ipa_col in header:
  				return header.index(self.ipa_col)
  
  			try:
  				ipa_col = int(self.ipa_col)
  			except ValueError: pass
  			else:
  				return ipa_col
  
  			raise ValueError('Could not find column: {}'.format(self.ipa_col))
  
  		pot = []
  
  		for index, col_name in enumerate(header):
  			col_name = col_name.lower()
  			for name in IPA_COL_NAMES:
  				if col_name.startswith(name):
  					pot.append(index)
  
  		if len(pot) == 0:
  			raise ValueError('Could not find an IPA column')
  		elif len(pot) > 1:
  			raise ValueError('Could not decide which is the IPA column')
  
  		return pot[0]
docs: Returns the column (as index) containing the IPA data based on the
  		header (the first line of the data file). Raises ValueError otherwise.
  
  		If self.ipa_col is a string, it is assumed to be the column's name or
  		index. Otherwise, several common IPA column names are tried.