more descriptive args in docstrings

[averagehat]

Just a note that a contracts-compatible alternative to the :type tag is the :param tag which can incude a doc of the arg as well.

@contract
def write_summary(data, outfile, delim='\t'): # data is 2d list
    ''' write data as a csv/tsv file to outfile.
    :type data:    Iterable
  etc."""

could be written as:

@contract
def write_summary(data, outfile, delim='\t'): # data is 2d list
    ''' write data as a csv/tsv file to outfile.
    :param   Iterable data: some docs
    :param str,!exists outfile: more docs ..
    etc '''