[pyqgis] __repr__ method for QgsExpression, QgsField (#7464)

* [pyqgis] __repr__ method for QgsExpression, QgsField

* add tests for __repr__ methods

* Fix test

python/core/auto_generated/expression/qgsexpression.sip.in

@@ -586,6 +586,12 @@ value. The value may be null.
 .. versionadded:: 3.0
 %End
 
+    SIP_PYOBJECT __repr__();
+%MethodCode
+    QString str = QStringLiteral( "<QgsExpression: '%1'>" ).arg( sipCpp->expression() );
+    sipRes = PyUnicode_FromString( str.toUtf8().data() );
+%End
+
 };
 
 

python/core/auto_generated/qgsfield.sip.in

@@ -330,6 +330,12 @@ by manual field configuration.
 :return: the value
 %End
 
+    SIP_PYOBJECT __repr__();
+%MethodCode
+    QString str = QStringLiteral( "<QgsField: %1 (%2)>" ).arg( sipCpp->name() ).arg( sipCpp->typeName() );
+    sipRes = PyUnicode_FromString( str.toUtf8().data() );
+%End
+
 }; // class QgsField
 
 

src/core/expression/qgsexpression.h

@@ -609,6 +609,14 @@ class CORE_EXPORT QgsExpression
      */
     static QString createFieldEqualityExpression( const QString &fieldName, const QVariant &value );
 
+#ifdef SIP_RUN
+    SIP_PYOBJECT __repr__();
+    % MethodCode
+    QString str = QStringLiteral( "<QgsExpression: '%1'>" ).arg( sipCpp->expression() );
+    sipRes = PyUnicode_FromString( str.toUtf8().data() );
+    % End
+#endif
+
   private:
     void initGeomCalculator();
 

src/core/qgsfield.h

@@ -335,6 +335,14 @@ class CORE_EXPORT QgsField
      */
     QgsEditorWidgetSetup editorWidgetSetup() const;
 
+#ifdef SIP_RUN
+    SIP_PYOBJECT __repr__();
+    % MethodCode
+    QString str = QStringLiteral( "<QgsField: %1 (%2)>" ).arg( sipCpp->name() ).arg( sipCpp->typeName() );
+    sipRes = PyUnicode_FromString( str.toUtf8().data() );
+    % End
+#endif
+
   private:
 
     QSharedDataPointer<QgsFieldPrivate> d;

tests/src/python/test_python_repr.py

@@ -14,9 +14,10 @@
 
 import qgis  # NOQA
 
+from PyQt5.QtCore import QVariant
 from qgis.testing import unittest, start_app
 from qgis.core import QgsGeometry, QgsPoint, QgsPointXY, QgsCircle, QgsCircularString, QgsCompoundCurve,\
-    QgsCurvePolygon, QgsEllipse, QgsLineString, QgsMultiCurve, QgsRectangle
+    QgsCurvePolygon, QgsEllipse, QgsLineString, QgsMultiCurve, QgsRectangle, QgsExpression, QgsField
 
 start_app()
 
@@ -112,6 +113,14 @@ def testQgsRectangleRepr(self):
         r = QgsRectangle(1, 2, 3, 4)
         self.assertEqual(r.__repr__(), '<QgsRectangle: 1 2, 3 4>')
 
+    def testQgsExpressionRepr(self):
+        e = QgsExpression('my expression')
+        self.assertEqual(e.__repr__(), "<QgsExpression: 'my expression'>")
+
+    def testQgsFieldRepr(self):
+        f = QgsField('field_name', QVariant.Double, 'double')
+        self.assertEqual(f.__repr__(), "<QgsField: field_name (double)>")
+
 
 if __name__ == "__main__":
     unittest.main()