code: def write_params(self, outfile=None, force=False):
          
          if outfile is None:
              outfile = "params-"+self.name+".txt"
  
          ## Test if params file already exists?
          ## If not forcing, test for file and bail out if it exists
          if not force:
              if os.path.isfile(outfile):
                  raise IPyradWarningExit(PARAMS_EXISTS.format(outfile))
  
          with open(outfile, 'w') as paramsfile:
              ## Write the header. Format to 80 columns
              header = "------- ipyrad params file (v.{})".format(ip.__version__)
              header += ("-"*(80-len(header)))
              paramsfile.write(header)
  
              ## Whip through the current paramsdict and write out the current
              ## param value, the ordered dict index number. Also,
              ## get the short description from paramsinfo. Make it look pretty,
              ## pad nicely if at all possible.
              for key, val in self.paramsdict.iteritems():
                  ## If multiple elements, write them out comma separated
                  if isinstance(val, list) or isinstance(val, tuple):
                      paramvalue = ", ".join([str(i) for i in val])
                  else:
                      paramvalue = str(val)
  
                  ## skip deprecated params
                  if key in ["edit_cutsites", "trim_overhang"]:
                      continue
  
                  padding = (" "*(30-len(paramvalue)))
                  paramkey = self.paramsdict.keys().index(key)
                  paramindex = " ## [{}] ".format(paramkey)
                  LOGGER.debug(key, val, paramindex)
                  name = "[{}]: ".format(paramname(paramkey))
                  description = paraminfo(paramkey, short=True)
                  paramsfile.write("\n" + paramvalue + padding + \
                                          paramindex + name + description)
docs: Write out the parameters of this assembly to a file properly
          formatted as input for `ipyrad -p <params.txt>`. A good and
          simple way to share/archive parameter settings for assemblies.
          This is also the function that's used by __main__ to
          generate default params.txt files for `ipyrad -n`