All,
I have figured out a bit more. I can get the binary values from the service but I think they come back as a single string. How do I read that into an array? The code below will read the first number into the array and print it out but how would I read the whole thing into an array...I would like to skip the step of putting the raw binary numbers into a variable and instead read it directly into the binvalues array.
I have tried things like binvalues.read(rawData.read(4,size of array)) and a few other things but none of them work. I was hoping for a fromstream but no luck no that either.
Unless the data is huge you should probably just read it all into a string, then pass the string to binvalue like this:
binvalues = array.array('f')
rawData = urllib2.urlopen(...).read()binvalues.fromstring(rawData) binvalues.byteswap()
This is likely to be the fastest approach as all the looping happens internally to urllib2 and array. The only limitation is that both representations have to fit in memory at once.
Alternately you could wrap the rawData in a generator function which returns floats. Then pass the generator to binvalues.extend(). Something like this (untested):
import array, struct, urllib2
def generateFloats(rawDataStream):
while True:
s = rawData.read(4)
if len(s) < 4: return
f = struct.unpack('f', s) # prefix the 'f' with the correct byte-order
character...
yield fbinvalues = array.array('f')
rawDataStream = urllib2.urlopen(...)binvalues.extend(generateFloats(rawDataStream))
Kent
Thanks for any help. <CODE> binvalues = array.array('f')
rawData = urllib2.urlopen("http://dsd1u:7003/GRID:U:NOGAPS:2005041800:global_360x181:a ir_temp:ht_sfc:00020000:00000000:fcst_ops:0240")
binvalues.fromstring(rawData.read(4)) # 4 byte float
binvalues.byteswap()
print binvalues
</CODE>
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