python - CSV 输出顺序错误

Question

我正在将一些数据输出到 CSV 文件，但由于某种原因，该方法改变了它输出数据的方式。下面的代码是用于将对象输出到 CSV 文件的方法。

@staticmethod
def OutputCSV(csv_file):
    posts = ApplicationModel.ApplicationModel.getTwitterObjects()
    csv_columns = ['post','sentiment']
    with open(csv_file, 'w') as csvfile:
        writer = csv.writer(csvfile)
        writer.writerow(csv_columns)
        for TwitterObject.TwitterObject in posts:
            writer.writerow({
                TwitterObject.TwitterObject.post,
                TwitterObject.TwitterObject.sentiment
            })

下面的文本是输出的 CSV 文件的示例。

post,sentiment

b'@Angel4Rubio @ehillm @Arsenal welcott been shit since he came to the league.',neg

pos,"b'Leicester closer to title, Arsenal held: Leicester City need just five points to complete a fairytale Premier ... '"

pos,"b'Leicester closer to title, Arsenal held: Leicester City need just five points to complete a fairytale Premier ... '"

pos,"b' @premierleague: ""I\'m slightly disappointed we didn\'t take all three points"" - Allardyce on #SUNARS\n\nMore:  '"

pos,"b'Leicester closer to title, Arsenal held: Leicester City need just five points to complete a fairytale Premier ... '"

b' @MesutOzil1088: best. team. \xf0\x9f\x92\xaa\xf0\x9f\x8f\xbc\xf0\x9f\x98\x8e\n#yagunnersya #BeTheDifference #AFCvLCFC #Arsenal #bigpoints ',pos

"b'Walcott, arteta, flamini, giroud and per to be sold. Bring in Hummells, Xhaka, Kante and Aubaumayang. #arsenal'",neg

pos,b' @FootieFansKnow: Amongst all the madness there is always Hector #Arsenal #Sunderland #Wenger #UCLDraw #Topfour  '

Answer 1

改变

writer.writerow({
            TwitterObject.TwitterObject.post,
            TwitterObject.TwitterObject.sentiment
        })

到

writer.writerow([
            TwitterObject.TwitterObject.post,
            TwitterObject.TwitterObject.sentiment
        ])

set 元素如 dict 键是无序的。因此行为。您可以分析大型集合 s 的 x in s 并将其与 x in l 进行比较，其中 l = list(s) 。前者的查找是 O(1)，而后者是 O(n)。这是无序哈希查找的优点之一。