I'm attempting to build a process that helps me to evaluate the performance of weather stations. The script below operates on an MS Access database, brings back some data, and then loops through to pull out statistics. One such stat is the frequency of reports from the stations ('char_freq'). I have a collection of methods that operate on the data to return the 'char_freq' and this works great. However, when the process goes to insert the unique 'char_freq' into a nested dictionary the value gets put into ALL of the sub-keys for all of the weather stations. I have isolated (I think) the problem to the compound key assignment in the next-to-last line before the print statements. The result is that the last 'freq' to run throught the for loops gets posted to all of the sensor_numbers. Eventually the process will put in stats for the other keys in the nested dictionary, so that's why I have set up the dictionary this way.
Thanks in advance! run_flag=1 if run_flag > 0: distinctID = runSQL(Unique_IDs) distinctID = map(firstpart,distinctID) # converts the list of tuples that is returned to a list of numbers rain_raw_dict = dict.fromkeys(distinctID,{'N':-6999,'char_freq':-6999,'tip1':-6999,'tip2':-6999,'tip3':-6999,'tip4':-6999,'tip5':-6999,'tip6':-6999,'lost_rain':-6999}) rawList = runSQL(Rain_Raw_Count) temp_list = [110,140,650,1440] for sensor_count, sensor_number in enumerate(temp_list): # get the frequency of timer reports for each rain gauge # note that when a for loop is of the form "for X, x in enumerate(xList)", # X is an index value, and x is the value itself. timerList = [] for icount, i in enumerate(rawList): if i[0]==sensor_number: for jcount in range(icount+1,len(rawList)): # look ahead to the next values for comparison if rawList[jcount][0]==sensor_number: if rawList[icount][2]==rawList[jcount][2]: temp = rawList[jcount][1]-rawList[icount][1] timerList.append(temp) icount = jcount-1 break # now build a histogram of the time differences stored in "timerList" h = Histogram() timer = h.histo(timerList) sorted_timer = h.sorted_histo(timer) freq = h.characteristic_freq(sorted_timer) rain_raw_dict[sensor_number]['char_freq'] = sensor_number # <<<< here's the problem!! freq = -6999 print "ID = 110:",rain_raw_dict[110] print "ID = 140:",rain_raw_dict[140] print "ID = 650:",rain_raw_dict[650] print "ID = 1440:",rain_raw_dict[1440] -- http://mail.python.org/mailman/listinfo/python-list