[Pyparsing] Parsing multiple items into the same Dict

[George P. <ge...@ga...>]

Hi all,
    Given the following:

s = \
"""
a.clk  = "----____----____"
a.rst  = "--------________"

b.clk  = "____----____----"
b.x    = "________--------"
"""

TIMING_SPEC = OneOrMore(Regex('[-_]'))
GROUPNAME   = Word(alphanums) + Suppress('.')
SIGNAME     = Word(alphanums) + Suppress('=')

GRAMMAR     = ???

# --------

What would the grammar have to look like so I can get the
following kind of parse results?

In particular, I'm stuck on how to parse multiple items into
the same dict. In this case, I want to have a dict containing
GROUPNAMEs as keys. Each GROUPNAME dict contains one or more
'SIGNAME':TIMINGSPEC key/value pairs:

>>>d = GRAMMAR.parseString(s).asDict()

>>>d['a'].keys()
['clk', 'rst']

>>>d['b'].keys()
['clk', 'x']

>>>d['a']['clk']
----____----____

>>>d['a']['rst']
--------________

>>>d['b']['clk']
____----____----

>>>d['b']['x']
________--------

Thanks,
George