将多个元组组合成一个元组列表

Question

我有一系列元组，这些元组是通过循环 SQL 查询的结果及其参数输出的。到目前为止，我有：

  Answers = ((userId, p[0], questions, i[0]) for i in strQueryTemplateForAnswerColumn)
            AnswerList = []
            for i in Answers:
                AnswerList.append(i)
                print(AnswerList)

导致：

[(42, 1, 1, 3)]
[(296, 1, 1, 5)]
[(1358, 1, 1, -1)].....etc for a few thousand rows.

我要做的是将这些元组组合成一个元组列表，而不是将每个元组转换为一个列表。如：

[(42, 1, 1, 3), (296, 1, 1, 5), (1358, 1, 1, -1)]

这是为了最终将其转换为具有 4 列/标题的 pandas df。

这里是完整的代码供参考：

cursor = conn.cursor()
allSurveyID = cursor.execute("""SELECT SurveyId FROM dbo.[Survey]""").fetchall()

for a in allSurveyID:
p = a
currentSurveyIDs = cursor.execute("""
DECLARE @SurveyID INT = ?
                SELECT *
           FROM
           (
              SELECT
                 SurveyId,
                 QuestionId,
                 1 as InSurvey
              FROM
                 SurveyStructure
              WHERE
                 SurveyId = @SurveyID
              UNION
              SELECT 
                 @SurveyID as SurveyId,
                 Q.QuestionId,
                 0 as InSurvey
              FROM
                 Question as Q
              WHERE NOT EXISTS
              (
                 SELECT *
                 FROM SurveyStructure as S
                 WHERE S.SurveyId = @SurveyID AND S.QuestionId = Q.QuestionId
              )
           ) as t
           ORDER BY QuestionId
            """, p).fetchall()

    for b in currentSurveyIDs:
        survey = (b[0])
        questions = (b[1])
        InSurvey = (b[2])

        allUserID = cursor.execute("""SELECT UserId FROM dbo.[Answer] ORDER BY 
UserId""").fetchall()

        for i in allUserID:
            userId = i[0]

            if InSurvey == 1:
                strQueryTemplateForAnswerColumn = cursor.execute("""SELECT COALESCE 
                                  ((SELECT 
                                   a.Answer_Value
                                   FROM dbo.Answer a 
                                   WHERE a.UserId = ?
                                   AND a.SurveyId = ?
                                   AND a.QuestionId = ?
                                   ),-1) AS ANS_Q?""", userId, survey, questions, questions).fetchall()

                    Answers = ((userId, p[0], questions, i[0]) for i in 
                                        strQueryTemplateForAnswerColumn)
                    AnswerList = []
                    for i in Answers:
                       AnswerList.append(i)
                       print(AnswerList)

感谢您的意见

Answer 1

我认为您是在说您有一个类似 [(42, 1, 1, 3)] 的列表，并且您想将其转换为类似 (42, 1, 1, 3) 的列表。

你可以这样做：

listOfListOfTuples = [
    [(42, 1, 1, 3)],
    [(296, 1, 1, 5)],
    [(1358, 1, 1, -1)]
]

print(listOfListOfTuples)

listOfTuples = [x[0] for x in listOfListOfTuples]
print(listOfTuples)

输入：

[[(42, 1, 1, 3)], [(296, 1, 1, 5)], [(1358, 1, 1, -1)]]

输出：

[(42, 1, 1, 3), (296, 1, 1, 5), (1358, 1, 1, -1)]

Answer 2

感谢您的 cmets。这行得通。

AnswerCol = []
AnswerColNull = []

# Loop through Survey and retrieve SurveyIDs while executing query to return the SurveyIDs, QuestionIDs and whether
# the question is in the survey

for a in allSurveyID:
    p = a[0]
    currentSurveyIDs = cursor.execute("""

                    SELECT *
               FROM
               (
                  SELECT
                     SurveyId,
                     QuestionId,
                     1 as InSurvey
                  FROM
                     SurveyStructure
                  WHERE
                     SurveyId = ?
                  UNION
                  SELECT 
                     ? as SurveyId,
                     Q.QuestionId,
                     0 as InSurvey
                  FROM
                     Question as Q
                  WHERE NOT EXISTS
                  (
                     SELECT *
                     FROM SurveyStructure as S
                     WHERE S.SurveyId = ? AND S.QuestionId = Q.QuestionId
                  )
               ) as t
               ORDER BY QuestionId
                """, p, p, p).fetchall()

    # Assign columns from above query to variables
    for b in currentSurveyIDs:
        survey = (b[0])
        questions = (b[1])
        InSurvey = (b[2])

        # Get all UserIDs and assign to variable
        allUserID = cursor.execute("""SELECT UserId FROM dbo.[Answer] ORDER BY UserId""").fetchall()
        for c in allUserID:
            userId = c[0]

            # If the question is in the survey, proceed with the AnswerColumn template query
            if InSurvey == 1:

                strQueryTemplateForAnswerColumn = cursor.execute("""SELECT COALESCE 
                                      ((SELECT 
                                       a.Answer_Value
                                       FROM dbo.Answer a 
                                       WHERE a.UserId = ?
                                       AND a.SurveyId = ?
                                       AND a.QuestionId = ?
                                       ),-1) AS ANS_Q?""", userId, survey, questions, questions).fetchall()

                # Generate rows for the table by appending each value to a list, creating a row then appending
                # the rows to a list outside the for loop
                Answer_List = []
                for d in strQueryTemplateForAnswerColumn:
                    Answer_parts = userId, p, questions, d[0]
                    Answer_List.append(Answer_parts)
                AnswerColNull.append(Answer_List)

            # Same procedure for the NULL values: if the question is not in the survey, use NULL answer template
            # query
            elif InSurvey == 0:
                strQueryTemplateForNullColumnn = cursor.execute(""" SELECT NULL AS ANS_?""",
                                                                questions).fetchall()
                # Generate rows for the table by appending each value to a list, creating a row then appending
                # the rows to a list outside the for loop
                Answer_ListNull = []
                for e in strQueryTemplateForNullColumnn:
                    Answer_partsNull = userId, p, questions, e[0]
                    Answer_ListNull.append(Answer_partsNull)
                AnswerColNull.append(Answer_ListNull)

# Append the values only of each list, cast to a tuple then appended to another list
AnswerColValsNull = []
for f in AnswerColNull:
    AnswerColValsNull.append(tuple(f[0]))

AnswerColVals = []
for g in AnswerCol:
    AnswerColVals.append(tuple(g[0]))

# Combine the list containing UserID, SurveyID, QuestionID, and Answer_Value
# At this point all the information is in a list of tuples
final = AnswerColVals + AnswerColValsNull