Am 24.01.2012 00:13 schrieb Thomas Rachel:
[sorry, my Thunderbird kills the indentation]
And finally, you can make use of re.finditer() resp.
sensorre.finditer(). So you can do
sensorre = re.compile(r'\$(.)(.*?)\$') # note the change
theonebuffer = '$A1234$$B-10$$C987$' # for now
sensorresult = None # init it for later
for sensorresult in sensorre.finditer(theonebuffer):
sensor, value = sensorresult.groups()
# replace the self.SensorAValue concept with a dict
self.sensorvalues[sensor] = value
# and now, keep the rest
if sensorresult is not None:
# the for loop has done something - cut out the old stuff
# and keep a possible incomplete packet at the end
theonebuffer = theonebuffer[sensorresult.end():]
This removes the mentionned string copying as source of increased slowness.
But it has one major flaw: If you lose synchronization, it may happen
that only the data *between* the packets is returned - which are mostly
empty strings.
So it would be wise to either change the firmware of the device to use
different characters for starting end ending a packet, or to return
every data between "$"s and discarding the empty strings.
As regexes might be overkill here, we could do
def splitup(theonebuffer):
l = theonebuffer.split("$")
for i in l[:-1]: yield i + "$"
if l: yield l[-1]
sensorvalues = {}
theonebuffer = '1garbage$A1234$$B-10$2garbage$C987$D3' # for now
for part in splitup(theonebuffer):
if not part.endswith("$"):
theonebuffer = part
break # it is the last one which is probably not a full packet
part = part[:-1] # cut off the $
if not part: continue # $$ -> gap between packets
# now part is the contents of one packet which may be valid or not.
# TODO: Do some tests - maybe for valid sensor names and values.
sensor = part[0]
value = part[1:]
sensorvalues[sensor] = value # add the "self." in your case -
# for now, it is better without
Now I get sensorvalues, theonebuffer as ({'1': 'garbage', 'A': '1234',
'2': 'garbage', 'B': '-10', 'C': '987'}, 'D3').
D3 is not (yet) a value; it might come out as D3, D342 or whatever, as
the packet is not complete yet.
Thomas
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