Python中添加對象的for循環

我有下面的代碼Python中添加對象的for循環

old_county_code = -1 
    old_placement_id = -1 
    placements = [] 
    for row in raw_data: #raw_data is one line from the database retrieved by cursor.fetchall() 

     placement_id = row[1] 
     if placement_id != old_placement_id: 
      placement = Objects.placement() 
      placement.placement_id = placement_id 
      placements.append(placement) 

     country_code = row[3] 
     if old_county_code != country_code: 
      country = Objects.country() 
      country.country_id = country_code 
      placement.countries.append(country)     

     creative = Objects.creative(row[2], row[0], row[4], row[5], row[6], row[7]) 
     country.creatives.append(creative) 

     old_placement_id = placement_id 
     old_county_code = country_code

對象配置包含本身包含廣告的列表國家名單。因此，當我運行此代碼時，我注意到每個展示位置都包含與列表對象placement.countries中包含的國家對象完全相同的數量。事實上，情況並非如此。我認爲我在代碼中做了一些錯誤，但我不知道是什麼。

這是對象的代碼

class placement(object): 
    placement_id = 0 
    countries = [] 

class country(object): 
    country_id = 0 
    creatives = [] 

class creative(object): 
    creative_id = 0 
    matching_id = 0 
    clicks = 0 
    impressions = 0 
    ctr = 0.0 
    rank = 0.0

來源

2012-09-03 toom

不知道你的努力從您的文章做......做一個小例子（非常小），並顯示所有輸入和所有輸出然後把你的預期輸出 –

另請參見[這個問題]（http://stackoverflow.com/questions/8860447/why-does-python-seem-to-treat -instance變量-作爲共享對象之間-）。這是一個「類與實例」變量問題。 – DSM

http://sscce.org/ – Marcin

使基礎，而不是基於類的內部變量實例....

class placement(object): 
    def __init__(self): 
    self.placement_id = 0 
    self.countries = [] 

class country(object): 
    def __init__(self): 
    self.country_id = 0 
    self.creatives = [] 

class creative(object): 
    def __init__(self) 
    self.creative_id = 0 
    self.matching_id = 0 
    self.clicks = 0 
    self.impressions = 0 
    self.ctr = 0.0 
    self.rank = 0.0

來源

2012-09-03 20:36:51

Python中添加對象的for循環

回答

相關問題