rhodri at wildebst
Nov 5, 2009, 4:42 PM
Post #4 of 5
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Re: parse a string (Cadence Allegro Netlist) to dictionary
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On Thu, 05 Nov 2009 20:02:53 -0000, Leland <lelandpeng[at]gmail.com> wrote:
> Hi,
>
> I always use readline(), strip(), split() and so on to parse a string.
> Is there some elegant way to parse the following string into a
> dictionary {'50MHZ_CLK_SRC' : 'U122.2, R1395.1'}?
>
> NET_NAME
> '50MHZ_CLK_SRC'
> '@TEST_LIB.TEST(SCH_1):50MHZ_CLK_SRC':
> C_SIGNAL='@test_lib.test(sch_1):\50mhz_clk_src\';
> NODE_NAME U122 2
> '@TEST_LIB.TEST(SCH_1):PAGE92_I223[at]INF_LOGIC.CY2305(CHIPS)':
> 'CLK2': CDS_PINID='CLK2';
> NODE_NAME R1395 1
> '@TEST_LIB.TEST(SCH_1):PAGE92_I232[at]INF_RESISTORS.RESISTOR(CHIPS)':
> 'A': CDS_PINID='A';
Here's an inelegant way:
**** CODE ****
results = {}
net_name_next = False
net_name = None
node_names = []
for line in sourcefile:
line = line.strip()
if line.startswith('NET_NAME'):
if net_name is not None:
results[net_name] = ", ".join(node_names)
net_name = None
node_names = []
net_name_next = True
elif net_name_next:
net_name = line.strip("'")
net_name_next = False
elif line.startswith('NODE_NAME'):
node_names.append("{1}.{2}".format(*line.split()))
# Last time through
if net_name is not None:
results[net_name] = ", ".join(node_names)
**** END CODE ****
If you're prepared to allow the dictionary values to be lists rather than
strings, we can squash that down:
**** CODE ****
results = {None: []}
net_name = None
for line in sourcefile:
line = line.strip()
if line.startswith('NET_NAME'):
net_name = sourcefile.next().strip(" \t\n'")
results[net_name] = []
elif line.startswith('NODE_NAME'):
results[net_name].append("{1}.{2}".format(*line.split()))
del results[None]
**** END CODE ****
If you can guarantee that you won't meet a NODE_NAME before you see a
NET_NAME then you can lose the messing about with results[None]. Having
spent today picking up the pieces from an assumption that's rotted after
several years, I'm not feeling that brave. A slightly less messy version
of that would be:
**** CODE ****
results = {}
entry = []
for line in sourcefile:
line = line.strip()
if line.startswith('NET_NAME'):
entry = []
results[sourcefile.next().strip(" \t\n'")] = entry
elif line.startswith('NODE_NAME'):
entry.append("{1}.{2}".format(*line.split()))
**** END CODE ****
I'm a little dubious about doing mutable magic like this without copious
comments, though.
--
Rhodri James *-* Wildebeest Herder to the Masses
--
http://mail.python.org/mailman/listinfo/python-list
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