Python試圖重構（DRY out）長的控制流

Question

我從中獲取了大量數據，並且SQL查詢需要很長時間才能運行。 由於SQL查詢需要很長時間才能運行，因此我以最精細的形式從數據庫中獲取數據。 然后，我循環瀏覽這些數據一次，並以對我有用的形式對其進行匯總。

我的問題是我一遍又一遍地重復自己。 但是，我不確定重構此控制流的最佳方法。 提前致謝！

def processClickOutData(cls, raw_data):
    singles = {}
    total={}
    absolute_total = 0
    channels = {}

    singles_true = {}
    total_true={}
    channels_true = {}
    absolute_total_true = 0

    list_channels = set([])
    list_tids = set([])


    total_position = {}
    total_position_true = {}
    tid_position = {}
    channel_position = {}
    channel_position_true = {}
    tid_position_true = {}

    for row in raw_data:
        gap=row[0]
        count=row[1]
        tid=row[2]
        prefered=row[3]
        channel=row[4]
        position=row[5]

        list_channels.add(channel)
        list_tids.add(tid)


        absolute_total += int(count)

        if total.has_key(gap):
            total[gap] += count
        else:
            total[gap] = count

        if singles.has_key(gap) and singles[gap].has_key(tid):
            singles[gap][tid] += count
        elif singles.has_key(gap):
            singles[gap][tid] = count
        else:
            singles[gap] = {}
            singles[gap][tid] = count

        if channels.has_key(gap) and channels[gap].has_key(channel):
            channels[gap][channel] += count
        elif channels.has_key(gap):
            channels[gap][channel] = count
        else:
            channels[gap] = {}
            channels[gap][channel] = count
        if total_position.has_key(position):
            total_position[position] += count
        else:
            total_position[position] = count
        if tid_position.has_key(position) and tid_position[position].has_key(tid):
            tid_position[position][tid] += count     
        elif tid_position.has_key(position):
            tid_position[position][tid] = count
        else:
            tid_position[position] = {}
            tid_position[position][tid] = count

        if channel_position.has_key(position) and channel_position[position].has_key(channel):
            channel_position[position][channel] += count     
        elif channel_position.has_key(position):
            channel_position[position][channel] = count
        else:
            channel_position[position] = {}
            channel_position[position][channel] = count

        if prefered == 0:
            absolute_total_true += count
            if total_true.has_key(gap):
                total_true[gap] += count
            else:
                total_true[gap] = count

            if singles_true.has_key(gap) and singles_true[gap].has_key(tid):
                singles_true[gap][tid] += count
            elif singles_true.has_key(gap):
                singles_true[gap][tid] = count
            else:
                singles_true[gap] = {}
                singles_true[gap][tid] = count

            if channels_true.has_key(gap) and channels_true[gap].has_key(channel):
               channels_true[gap][channel] += count
            elif channels_true.has_key(gap):
               channels_true[gap][channel] = count
            else:
               channels_true[gap] = {}
               channels_true[gap][channel] = count

            if total_position_true.has_key(position):
               total_position_true[position] += count
            else:
               total_position_true[position] = count 

            if tid_position_true.has_key(position) and tid_position_true[position].has_key(tid):
               tid_position_true[position][tid] += count     
            elif tid_position_true.has_key(position):
               tid_position_true[position][tid] = count
            else:
               tid_position_true[position] = {}
               tid_position_true[position][tid] = count

            if channel_position_true.has_key(position) and channel_position_true[position].has_key(channel):
               channel_position_true[position][channel] += count     
            elif channel_position_true.has_key(position):
               channel_position_true[position][channel] = count
            else:
               channel_position_true[position] = {}
               channel_position_true[position][channel] = count




    final_values = {"singles" : singles, "singles_true" : singles_true, "total" : total, "total_true": total_true, "absolute_total": absolute_total, "absolute_total_true": absolute_total_true, "channel_totals" : channels, "list_channels" : list_channels, "list_tids" : list_tids, "channel_totals_true" : channels_true,
                     "total_position" :  total_position, "total_position_true" : total_position_true, "tid_position" : tid_position, "channel_position" : channel_position, "tid_position_true" : tid_position_true, "channel_position_true" : channel_position_true }
    return final_values

Answer 1

您用來存儲數據的整個結構可能是錯誤的，但是由於我不知道您如何使用它，因此我無法為您提供幫助。

您可以使用collections.defaultdict擺脫所有的has_key()調用。 注意thedict.has_key(key)仍然被棄用，您應該只key in thedict使用key in thedict 。

再看看我如何更改for循環-您可以直接在for語句中分配名稱，而無需單獨進行操作。

from collections import defaultdict

def processClickOutData(cls, raw_data):
    absolute_total = 0
    absolute_total_true = 0

    list_channels = set()
    list_tids = set()

    total = defaultdict(int)
    total_true = defaultdict(int)
    total_position = defaultdict(int)
    total_position_true = defaultdict(int)

    def defaultdict_int():
        return defaultdict(int)

    singles = defaultdict(defaultdict_int)
    singles_true = defaultdict(defaultdict_int)
    channels = defaultdict(defaultdict_int)
    channels_true = defaultdict(defaultdict_int)
    tid_position = defaultdict(defaultdict_int)
    tid_position_true = defaultdict(defaultdict_int)
    channel_position = defaultdict(defaultdict_int)
    channel_position_true = defaultdict(defaultdict_int)    

    for gap, count, prefered, channel, position in raw_data:
        list_channels.add(channel)
        list_tids.add(tid)

        absolute_total += count
        total[gap] += count
        singles[gap][tid] += count
        channels[gap][channel] += count
        total_position[position] += count
        tid_position[position][tid] += count
        channel_position[position][channel] += count

        if prefered == 0:
            absolute_total_true += count
            total_true[gap] += count
            singles_true[gap][tid] += count
            channels_true[gap][channel] += count
            total_position_true[position] += count
            tid_position_true[position][tid] += count
            channel_position_true[position][channel] += count




    final_values = {"singles" : singles, "singles_true" : singles_true, "total" : total, "total_true": total_true, "absolute_total": absolute_total, "absolute_total_true": absolute_total_true, "channel_totals" : channels, "list_channels" : list_channels, "list_tids" : list_tids, "channel_totals_true" : channels_true,
                     "total_position" :  total_position, "total_position_true" : total_position_true, "tid_position" : tid_position, "channel_position" : channel_position, "tid_position_true" : tid_position_true, "channel_position_true" : channel_position_true }
    return final_values

如果這些鍵不存在，它將自動填寫正確的默認值。 您在這里有兩種。 在添加int的位置，如果它不存在， defaultdict(int)以0開頭-這就是int返回的內容，因此是defaultdict(int) 。 在添加添加int的字典的地方，需要使用一個返回defaultdict(int)的函數，該函數就是defaultdict_int所做的事情。

編輯：建議的備用字典結構：

position = defaultdict(lambda: defaultdict(defaultdict_int))
gap = defaultdict(lambda: defaultdict(defaultdict_int))
absolute_total = 0

for gap, count, prefered, channel, position in raw_data:
    absolute_total += count

    posd = position[position]
    posd.setdefault('total', 0)
    posd['total'] += count
    posd['tid'][tid] += count
    posd['channel'][channel] += count

    gapd = gap[gap]
    gapd.setdefault('total', 0)
    gapd['total'] += count
    gapd['tid'][tid] += count
    gapd['channel'][channel] += count

對_true版本也執行相同的_true ，而您從12 dict變為4。