Add model example with Pandas DataFrame

Create a PandasModel working with a QTableView to show DataFrame from
Pandas library

patch : add missing pyproject

Change-Id: I16e2580f3fceba34a2491354394b3c78dd981a98
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>
Reviewed-by: Christian Tismer <tismer@stackless.com>
(cherry picked from commit b9aa61247c355a9330e52059951649c6ba7697c2)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 274 insertions, 0 deletions

diff --git a/examples/external/pandas/dataframe_model.py b/examples/external/pandas/dataframe_model.py
new file mode 100644
index 000000000..b3f92f562
--- /dev/null
+++ b/examples/external/pandas/dataframe_model.py
@@ -0,0 +1,119 @@
+#############################################################################
+##
+## Copyright (C) 2021 The Qt Company Ltd.
+## Contact: https://www.qt.io/licensing/
+##
+## This file is part of the Qt for Python examples of the Qt Toolkit.
+##
+## $QT_BEGIN_LICENSE:BSD$
+## You may use this file under the terms of the BSD license as follows:
+##
+## "Redistribution and use in source and binary forms, with or without
+## modification, are permitted provided that the following conditions are
+## met:
+##   * Redistributions of source code must retain the above copyright
+##     notice, this list of conditions and the following disclaimer.
+##   * Redistributions in binary form must reproduce the above copyright
+##     notice, this list of conditions and the following disclaimer in
+##     the documentation and/or other materials provided with the
+##     distribution.
+##   * Neither the name of The Qt Company Ltd nor the names of its
+##     contributors may be used to endorse or promote products derived
+##     from this software without specific prior written permission.
+##
+##
+## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+import pandas as pd
+
+from PySide6.QtWidgets import QTableView, QApplication
+from PySide6.QtCore import QAbstractTableModel, Qt, QModelIndex
+import sys
+
+
+class PandasModel(QAbstractTableModel):
+    """A model to interface a Qt view with pandas dataframe """
+
+    def __init__(self, dataframe: pd.DataFrame, parent=None):
+        QAbstractTableModel.__init__(self, parent)
+        self._dataframe = dataframe
+
+    def rowCount(self, parent=QModelIndex()) -> int:
+        """ Override method from QAbstractTableModel
+
+        Return row count of the pandas DataFrame
+        """
+        if parent == QModelIndex():
+            return len(self._dataframe)
+
+        return 0
+
+    def columnCount(self, parent=QModelIndex()) -> int:
+        """Override method from QAbstractTableModel
+
+        Return column count of the pandas DataFrame
+        """
+        if parent == QModelIndex():
+            return len(self._dataframe.columns)
+        return 0
+
+    def data(self, index: QModelIndex, role=Qt.ItemDataRole):
+        """Override method from QAbstractTableModel
+
+        Return data cell from the pandas DataFrame
+        """
+        if not index.isValid():
+            return None
+
+        if role == Qt.DisplayRole:
+            return str(self._dataframe.iloc[index.row(), index.column()])
+
+        return None
+
+    def headerData(
+        self, section: int, orientation: Qt.Orientation, role: Qt.ItemDataRole
+    ):
+        """Override method from QAbstractTableModel
+
+        Return dataframe index as vertical header data and columns as horizontal header data.
+        """
+        if role == Qt.DisplayRole:
+            if orientation == Qt.Horizontal:
+                return str(self._dataframe.columns[section])
+
+            if orientation == Qt.Vertical:
+                return str(self._dataframe.index[section])
+
+        return None
+
+
+if __name__ == "__main__":
+
+    app = QApplication(sys.argv)
+
+    df = pd.read_csv("iris.csv")
+
+    view = QTableView()
+    view.resize(800, 500)
+    view.horizontalHeader().setStretchLastSection(True)
+    view.setAlternatingRowColors(True)
+    view.setSelectionBehavior(QTableView.SelectRows)
+
+    model = PandasModel(df)
+    view.setModel(model)
+    view.show()
+    app.exec_()
diff --git a/examples/external/pandas/iris.csv b/examples/external/pandas/iris.csv
new file mode 100644
index 000000000..bf14e161b
--- /dev/null
+++ b/examples/external/pandas/iris.csv
@@ -0,0 +1,151 @@
+"sepal.length","sepal.width","petal.length","petal.width","variety"
+5.1,3.5,1.4,.2,"Setosa"
+4.9,3,1.4,.2,"Setosa"
+4.7,3.2,1.3,.2,"Setosa"
+4.6,3.1,1.5,.2,"Setosa"
+5,3.6,1.4,.2,"Setosa"
+5.4,3.9,1.7,.4,"Setosa"
+4.6,3.4,1.4,.3,"Setosa"
+5,3.4,1.5,.2,"Setosa"
+4.4,2.9,1.4,.2,"Setosa"
+4.9,3.1,1.5,.1,"Setosa"
+5.4,3.7,1.5,.2,"Setosa"
+4.8,3.4,1.6,.2,"Setosa"
+4.8,3,1.4,.1,"Setosa"
+4.3,3,1.1,.1,"Setosa"
+5.8,4,1.2,.2,"Setosa"
+5.7,4.4,1.5,.4,"Setosa"
+5.4,3.9,1.3,.4,"Setosa"
+5.1,3.5,1.4,.3,"Setosa"
+5.7,3.8,1.7,.3,"Setosa"
+5.1,3.8,1.5,.3,"Setosa"
+5.4,3.4,1.7,.2,"Setosa"
+5.1,3.7,1.5,.4,"Setosa"
+4.6,3.6,1,.2,"Setosa"
+5.1,3.3,1.7,.5,"Setosa"
+4.8,3.4,1.9,.2,"Setosa"
+5,3,1.6,.2,"Setosa"
+5,3.4,1.6,.4,"Setosa"
+5.2,3.5,1.5,.2,"Setosa"
+5.2,3.4,1.4,.2,"Setosa"
+4.7,3.2,1.6,.2,"Setosa"
+4.8,3.1,1.6,.2,"Setosa"
+5.4,3.4,1.5,.4,"Setosa"
+5.2,4.1,1.5,.1,"Setosa"
+5.5,4.2,1.4,.2,"Setosa"
+4.9,3.1,1.5,.2,"Setosa"
+5,3.2,1.2,.2,"Setosa"
+5.5,3.5,1.3,.2,"Setosa"
+4.9,3.6,1.4,.1,"Setosa"
+4.4,3,1.3,.2,"Setosa"
+5.1,3.4,1.5,.2,"Setosa"
+5,3.5,1.3,.3,"Setosa"
+4.5,2.3,1.3,.3,"Setosa"
+4.4,3.2,1.3,.2,"Setosa"
+5,3.5,1.6,.6,"Setosa"
+5.1,3.8,1.9,.4,"Setosa"
+4.8,3,1.4,.3,"Setosa"
+5.1,3.8,1.6,.2,"Setosa"
+4.6,3.2,1.4,.2,"Setosa"
+5.3,3.7,1.5,.2,"Setosa"
+5,3.3,1.4,.2,"Setosa"
+7,3.2,4.7,1.4,"Versicolor"
+6.4,3.2,4.5,1.5,"Versicolor"
+6.9,3.1,4.9,1.5,"Versicolor"
+5.5,2.3,4,1.3,"Versicolor"
+6.5,2.8,4.6,1.5,"Versicolor"
+5.7,2.8,4.5,1.3,"Versicolor"
+6.3,3.3,4.7,1.6,"Versicolor"
+4.9,2.4,3.3,1,"Versicolor"
+6.6,2.9,4.6,1.3,"Versicolor"
+5.2,2.7,3.9,1.4,"Versicolor"
+5,2,3.5,1,"Versicolor"
+5.9,3,4.2,1.5,"Versicolor"
+6,2.2,4,1,"Versicolor"
+6.1,2.9,4.7,1.4,"Versicolor"
+5.6,2.9,3.6,1.3,"Versicolor"
+6.7,3.1,4.4,1.4,"Versicolor"
+5.6,3,4.5,1.5,"Versicolor"
+5.8,2.7,4.1,1,"Versicolor"
+6.2,2.2,4.5,1.5,"Versicolor"
+5.6,2.5,3.9,1.1,"Versicolor"
+5.9,3.2,4.8,1.8,"Versicolor"
+6.1,2.8,4,1.3,"Versicolor"
+6.3,2.5,4.9,1.5,"Versicolor"
+6.1,2.8,4.7,1.2,"Versicolor"
+6.4,2.9,4.3,1.3,"Versicolor"
+6.6,3,4.4,1.4,"Versicolor"
+6.8,2.8,4.8,1.4,"Versicolor"
+6.7,3,5,1.7,"Versicolor"
+6,2.9,4.5,1.5,"Versicolor"
+5.7,2.6,3.5,1,"Versicolor"
+5.5,2.4,3.8,1.1,"Versicolor"
+5.5,2.4,3.7,1,"Versicolor"
+5.8,2.7,3.9,1.2,"Versicolor"
+6,2.7,5.1,1.6,"Versicolor"
+5.4,3,4.5,1.5,"Versicolor"
+6,3.4,4.5,1.6,"Versicolor"
+6.7,3.1,4.7,1.5,"Versicolor"
+6.3,2.3,4.4,1.3,"Versicolor"
+5.6,3,4.1,1.3,"Versicolor"
+5.5,2.5,4,1.3,"Versicolor"
+5.5,2.6,4.4,1.2,"Versicolor"
+6.1,3,4.6,1.4,"Versicolor"
+5.8,2.6,4,1.2,"Versicolor"
+5,2.3,3.3,1,"Versicolor"
+5.6,2.7,4.2,1.3,"Versicolor"
+5.7,3,4.2,1.2,"Versicolor"
+5.7,2.9,4.2,1.3,"Versicolor"
+6.2,2.9,4.3,1.3,"Versicolor"
+5.1,2.5,3,1.1,"Versicolor"
+5.7,2.8,4.1,1.3,"Versicolor"
+6.3,3.3,6,2.5,"Virginica"
+5.8,2.7,5.1,1.9,"Virginica"
+7.1,3,5.9,2.1,"Virginica"
+6.3,2.9,5.6,1.8,"Virginica"
+6.5,3,5.8,2.2,"Virginica"
+7.6,3,6.6,2.1,"Virginica"
+4.9,2.5,4.5,1.7,"Virginica"
+7.3,2.9,6.3,1.8,"Virginica"
+6.7,2.5,5.8,1.8,"Virginica"
+7.2,3.6,6.1,2.5,"Virginica"
+6.5,3.2,5.1,2,"Virginica"
+6.4,2.7,5.3,1.9,"Virginica"
+6.8,3,5.5,2.1,"Virginica"
+5.7,2.5,5,2,"Virginica"
+5.8,2.8,5.1,2.4,"Virginica"
+6.4,3.2,5.3,2.3,"Virginica"
+6.5,3,5.5,1.8,"Virginica"
+7.7,3.8,6.7,2.2,"Virginica"
+7.7,2.6,6.9,2.3,"Virginica"
+6,2.2,5,1.5,"Virginica"
+6.9,3.2,5.7,2.3,"Virginica"
+5.6,2.8,4.9,2,"Virginica"
+7.7,2.8,6.7,2,"Virginica"
+6.3,2.7,4.9,1.8,"Virginica"
+6.7,3.3,5.7,2.1,"Virginica"
+7.2,3.2,6,1.8,"Virginica"
+6.2,2.8,4.8,1.8,"Virginica"
+6.1,3,4.9,1.8,"Virginica"
+6.4,2.8,5.6,2.1,"Virginica"
+7.2,3,5.8,1.6,"Virginica"
+7.4,2.8,6.1,1.9,"Virginica"
+7.9,3.8,6.4,2,"Virginica"
+6.4,2.8,5.6,2.2,"Virginica"
+6.3,2.8,5.1,1.5,"Virginica"
+6.1,2.6,5.6,1.4,"Virginica"
+7.7,3,6.1,2.3,"Virginica"
+6.3,3.4,5.6,2.4,"Virginica"
+6.4,3.1,5.5,1.8,"Virginica"
+6,3,4.8,1.8,"Virginica"
+6.9,3.1,5.4,2.1,"Virginica"
+6.7,3.1,5.6,2.4,"Virginica"
+6.9,3.1,5.1,2.3,"Virginica"
+5.8,2.7,5.1,1.9,"Virginica"
+6.8,3.2,5.9,2.3,"Virginica"
+6.7,3.3,5.7,2.5,"Virginica"
+6.7,3,5.2,2.3,"Virginica"
+6.3,2.5,5,1.9,"Virginica"
+6.5,3,5.2,2,"Virginica"
+6.2,3.4,5.4,2.3,"Virginica"
+5.9,3,5.1,1.8,"Virginica"
diff --git a/examples/external/pandas/pandas.pyproject b/examples/external/pandas/pandas.pyproject
new file mode 100644
index 000000000..4731cf7d9
--- /dev/null
+++ b/examples/external/pandas/pandas.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["dataframe_model.py"]
+}
diff --git a/examples/external/pandas/requirements.txt b/examples/external/pandas/requirements.txt
new file mode 100644
index 000000000..fb6c7ed7e
--- /dev/null
+++ b/examples/external/pandas/requirements.txt
@@ -0,0 +1 @@
+pandas