PyQt - 使用 pandas DataFrame 在 QAbstractTableModel (QTableView) 中加载 SQL - 在 GUI 中编辑数据

Question

我对 python 和使用都很陌生WinPython-32bit-2.7.10.3（包括QTDesigner 4.8.7。我正在尝试使用 QtableViews 编写一个接口，以便在两个独立的项目上使用 sqlite 数据库。

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该算法大致如下：
\n- 连接到数据库并将数据转换为pandas.DataFrame
\n- 将 DataFrame 转换为 QAbstractTableModel
\n- 将 QAbstractTableModel 应用到tableview.model
\n- 加载对话框

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我没有得到相同的行为，具体取决于用于创建数据帧的 sql：\n给定一个 SQL 表“参数”，具有 3 个字段（LIBELLE 作为 varchar，VALEUR 作为 varchar，TEST 作为布尔值），尝试的 sql 是：

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• \'从参数中选择 LIBELLE AS "Param\xc3\xa8tre", VALEUR AS "Valeur"\'.encode("utf-8")
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• \'SELECT * FROM 参数\'.encode("utf-8")
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通过第一个请求，我可以编辑表格视图内的数据。对于第二个请求，我可以选择一个“单元格”，对其进行编辑，但是当我提交版本（按 Enter 键）时，数据将设置回其第一个值。

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在搜索时，我发现无论“任何”值是什么，setData 代码的这一行都不起作用：

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self._data.values[index.row()][index.column()] = "anything"\n

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您可以通过删除主代码中第27行开头的#字符来测试sql源的发生率。

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我已将代码截断到严格的最低限度（非常接近我的第一个项目的原始工作代码），并且我感到非常困惑。如果有人有想法，那就太好了！

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谢谢

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PS：我后来发布了代码，但我还没有找到加入的方法sqlite.db...如果有人可以指导我，我会很高兴添加它；与此同时，我已经在我的google.drive上加入了该地段的整个 zip

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---

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编辑#2：

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仍然无法理解那里出了什么问题，但我刚刚发现一旦加载数据就无法将数据提交到模型。我很确定这是我问题的核心，并随后更新了问题和标题。

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---

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主要代码：

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#\xc2\xad*\xc2\xadcoding: utf\xc2\xad8 \xc2\xad*\xc2\xad\n\nfrom PyQt4 import QtCore, QtGui\n\nimport os,sys\nfrom parametrage import Ui_WinParam\nfrom PANDAS_TO_PYQT import PandasModel\n\nimport pandas as pd\nimport sqlite3\n\nclass window_parametreur(QtGui.QDialog, Ui_WinParam):\n    def __init__(self, dataframemodel, parent=None):        \n        QtGui.QDialog.__init__(self, parent)\n        # Set up the user interface from Designer.\n        self.ui = Ui_WinParam()\n        self.ui.setupUi(self)\n        self.setModal(True)        \n        self.ui.tableView.setModel(dataframemodel)\n        self.ui.tableView.resizeColumnsToContents()\n\ndef OpenParametreur(self, db_path):\n\n    #connecting to database and getting datas as pandas.dataframe\n    con = sqlite3.connect(db_path)\n    strSQL = u\'SELECT LIBELLE AS "Param\xc3\xa8tre", VALEUR AS "Valeur" FROM parametres\'.encode("utf-8")\n    #strSQL = u\'SELECT * FROM parametres\'.encode("utf-8")\n    data = pd.read_sql_query(strSQL, con)\n    con.close()\n\n    #converting to QtCore.QAbstractTableModel\n    model = PandasModel(data)\n\n    #loading dialog\n    self.f=window_parametreur(model)   \n    self.f.exec_()\n\nif __name__=="__main__":\n    a=QtGui.QApplication(sys.argv)\n    f=QtGui.QMainWindow()\n    print OpenParametreur(f, ".\\SQLiteDataBase.db")\n

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“PANDAS_TO_PYQT.py”的代码，被调用以将 pandas.dataframe 转换为 QtCore.QAbstractTableModel

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#\xc2\xad*\xc2\xadcoding: utf\xc2\xad8 \xc2\xad*\xc2\xad\n\nfrom PyQt4 import QtCore, QtGui\n\nclass PandasModel(QtCore.QAbstractTableModel):\n    def __init__(self, data, parent=None):\n        QtCore.QAbstractTableModel.__init__(self, parent)\n        self._data = data\n\n    def rowCount(self, parent=None):\n        return len(self._data.values)\n\n    def columnCount(self, parent=None):\n        return self._data.columns.size\n\n    def data(self, index, role=QtCore.Qt.DisplayRole):\n        if index.isValid():\n            if role == QtCore.Qt.DisplayRole or role == QtCore.Qt.EditRole:\n                return QtCore.QVariant(unicode(\n                    self._data.values[index.row()][index.column()]))\n        return QtCore.QVariant()\n\n    def headerData(self, section, orientation, role=QtCore.Qt.DisplayRole):\n        if role != QtCore.Qt.DisplayRole:\n            return None\n        if orientation == QtCore.Qt.Horizontal:\n            try:\n                return \'%s\' % unicode(self._data.columns.tolist()[section], encoding="utf-8")\n            except (IndexError, ):\n                return QtCore.QVariant()\n        elif orientation == QtCore.Qt.Vertical:\n            try:\n                return \'%s\' % self._data.index.tolist()[section]\n            except (IndexError, ):\n                return QtCore.QVariant()\n\n    def flags(self, index):\n        return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEditable\n\n    def setData(self, index, value, role=QtCore.Qt.EditRole):\n        if index.isValid():\n\n            print "data set with keyboard : " + value.toByteArray().data().decode("latin1")\n            self._data.values[index.row()][index.column()] = "anything"\n            print "data committed : " +self._data.values[index.row()][index.column()]\n\n            self.dataChanged.emit(index, index)\n            return True\n        return QtCore.QVariant()\n

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parametrage.py 的代码，由 QtDesigner 创建，包含对话框源：

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# -*- coding: utf-8 -*-\n\n# Form implementation generated from reading ui file \'parametrage.ui\'\n#\n# Created by: PyQt4 UI code generator 4.11.4\n#\n# WARNING! All changes made in this file will be lost!\n\nfrom PyQt4 import QtCore, QtGui\n\ntry:\n    _fromUtf8 = QtCore.QString.fromUtf8\nexcept AttributeError:\n    def _fromUtf8(s):\n        return s\n\ntry:\n    _encoding = QtGui.QApplication.UnicodeUTF8\n    def _translate(context, text, disambig):\n        return QtGui.QApplication.translate(context, text, disambig, _encoding)\nexcept AttributeError:\n    def _translate(context, text, disambig):\n        return QtGui.QApplication.translate(context, text, disambig)\n\nclass Ui_WinParam(object):\n    def setupUi(self, WinParam):\n        WinParam.setObjectName(_fromUtf8("WinParam"))\n        WinParam.resize(608, 279)\n        icon = QtGui.QIcon()\n        icon.addPixmap(QtGui.QPixmap(_fromUtf8("../../pictures/EAUX.png")), QtGui.QIcon.Normal, QtGui.QIcon.Off)\n        WinParam.setWindowIcon(icon)\n        self.gridLayout = QtGui.QGridLayout(WinParam)\n        self.gridLayout.setObjectName(_fromUtf8("gridLayout"))\n        self.ButtonBox = QtGui.QDialogButtonBox(WinParam)\n        self.ButtonBox.setOrientation(QtCore.Qt.Horizontal)\n        self.ButtonBox.setStandardButtons(QtGui.QDialogButtonBox.Cancel|QtGui.QDialogButtonBox.Ok)\n        self.ButtonBox.setCenterButtons(True)\n        self.ButtonBox.setObjectName(_fromUtf8("ButtonBox"))\n        self.gridLayout.addWidget(self.ButtonBox, 1, 0, 1, 1)\n        self.tableView = QtGui.QTableView(WinParam)\n        self.tableView.setEditTriggers(QtGui.QAbstractItemView.DoubleClicked)\n        self.tableView.setSortingEnabled(False)\n        self.tableView.setObjectName(_fromUtf8("tableView"))\n        self.gridLayout.addWidget(self.tableView, 0, 0, 1, 1)\n\n        self.retranslateUi(WinParam)\n        QtCore.QObject.connect(self.ButtonBox, QtCore.SIGNAL(_fromUtf8("accepted()")), WinParam.accept)\n        QtCore.QObject.connect(self.ButtonBox, QtCore.SIGNAL(_fromUtf8("rejected()")), WinParam.reject)\n        QtCore.QMetaObject.connectSlotsByName(WinParam)\n\n    def retranslateUi(self, WinParam):\n        WinParam.setWindowTitle(_translate("WinParam", "Param\xc3\xa9trage", None))\n\n\nif __name__ == "__main__":\n    import sys\n    app = QtGui.QApplication(sys.argv)\n    WinParam = QtGui.QDialog()\n    ui = Ui_WinParam()\n    ui.setupUi(WinParam)\n    WinParam.show()\n    sys.exit(app.exec_())\n

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Answer 1

我终于想通了...但我仍然不知道为什么 pandas 仅通过更改 SQL 请求就可以不同地工作（必须是 read_sql_query 过程中的某些内容...）

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为了让课程正常工作，我必须更改“PANDAS_TO_PYQT.py”的代码，替换

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self._data.values[index.row()][index.column()]\n

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经过

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self._data.iloc[index.row(),index.column()]\n

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在 setData 和 data 函数中。

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不知何故，pandas 似乎在这个过程中生成了数据帧的副本（对于那些寻找解释的人，请转到doc）。

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因此，将数据帧转换为 QAbstractTableModel 的正确类代码是：

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#\xc2\xad*\xc2\xadcoding: utf\xc2\xad8 \xc2\xad*\xc2\xad\n\nfrom PyQt4 import QtCore, QtGui\n\nclass PandasModel(QtCore.QAbstractTableModel):\n    def __init__(self, data, parent=None):\n        QtCore.QAbstractTableModel.__init__(self, parent)\n        self._data = data\n\n    def rowCount(self, parent=None):\n        return len(self._data.values)\n\n    def columnCount(self, parent=None):\n        return self._data.columns.size\n\n    def data(self, index, role=QtCore.Qt.DisplayRole):\n        if index.isValid():\n            if role == QtCore.Qt.DisplayRole or role == QtCore.Qt.EditRole:\n                return QtCore.QVariant(unicode(\n                    self._data.iloc[index.row(),index.column()]))\n        return QtCore.QVariant()\n\n    def headerData(self, section, orientation, role=QtCore.Qt.DisplayRole):\n        if role != QtCore.Qt.DisplayRole:\n            return None\n        if orientation == QtCore.Qt.Horizontal:\n            try:\n                return \'%s\' % unicode(self._data.columns.tolist()[section], encoding="utf-8")\n            except (IndexError, ):\n                return QtCore.QVariant()\n        elif orientation == QtCore.Qt.Vertical:\n            try:\n                return \'%s\' % self._data.index.tolist()[section]\n            except (IndexError, ):\n                return QtCore.QVariant()\n\n    def flags(self, index):\n        return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEditable\n\n    def setData(self, index, value, role=QtCore.Qt.EditRole):\n        if index.isValid():\n            self._data.iloc[index.row(),index.column()] = value.toByteArray().data().decode("latin1")\n            if self.data(index,QtCore.Qt.DisplayRole) == value.toByteArray().data().decode("latin1"):\n                self.dataChanged.emit(index, index)\n                return True\n        return QtCore.QVariant()\n

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