FEM: objs, use single quotes instead of double ones

src/Mod/Fem/femobjects/_FemElementFluid1D.py

@@ -33,24 +33,24 @@ __url__ = "http://www.freecadweb.org"
 class _FemElementFluid1D:
     "The FemElementFluid1D object"
 
-    known_fluid_types = ['Liquid']
-    # 'Gas', 'Open Channel' are not implemented in ccx writer
-    # known_fluid_types = ['Liquid', 'Gas', 'Open Channel']
+    known_fluid_types = ["Liquid"]
+    # "Gas", "Open Channel" are not implemented in ccx writer
+    # known_fluid_types = ["Liquid", "Gas", "Open Channel"]
     known_liquid_types = [
-        'PIPE MANNING',
-        'PIPE ENLARGEMENT',
-        'PIPE CONTRACTION',
-        'PIPE INLET',
-        'PIPE OUTLET',
-        'PIPE ENTRANCE',
-        'PIPE DIAPHRAGM',
-        'PIPE BEND',
-        'PIPE GATE VALVE',
-        'LIQUID PUMP',
-        'PIPE WHITE-COLEBROOK'
+        "PIPE MANNING",
+        "PIPE ENLARGEMENT",
+        "PIPE CONTRACTION",
+        "PIPE INLET",
+        "PIPE OUTLET",
+        "PIPE ENTRANCE",
+        "PIPE DIAPHRAGM",
+        "PIPE BEND",
+        "PIPE GATE VALVE",
+        "LIQUID PUMP",
+        "PIPE WHITE-COLEBROOK"
     ]
-    known_gas_types = ['NONE']
-    known_channel_types = ['NONE']
+    known_gas_types = ["NONE"]
+    known_channel_types = ["NONE"]
 
     def __init__(self, obj):
         obj.addProperty(
@@ -272,13 +272,13 @@ class _FemElementFluid1D:
 
         # set property default values
         obj.SectionType = _FemElementFluid1D.known_fluid_types
-        obj.SectionType = 'Liquid'
+        obj.SectionType = "Liquid"
         obj.LiquidSectionType = _FemElementFluid1D.known_liquid_types
-        obj.LiquidSectionType = 'PIPE INLET'
+        obj.LiquidSectionType = "PIPE INLET"
         obj.GasSectionType = _FemElementFluid1D.known_gas_types
-        obj.GasSectionType = 'NONE'
+        obj.GasSectionType = "NONE"
         obj.ChannelSectionType = _FemElementFluid1D.known_channel_types
-        obj.ChannelSectionType = 'NONE'
+        obj.ChannelSectionType = "NONE"
         obj.ManningArea = 10.0
         obj.ManningRadius = 1.0
         obj.ManningCoefficient = 0.0015  # has units of s/mm^(1/3)

src/Mod/Fem/femobjects/_FemElementGeometry1D.py

@@ -32,7 +32,7 @@ __url__ = "http://www.freecadweb.org"
 class _FemElementGeometry1D:
     "The FemElementGeometry1D object"
 
-    known_beam_types = ['Rectangular', 'Circular', 'Pipe']
+    known_beam_types = ["Rectangular", "Circular", "Pipe"]
 
     def __init__(self, obj):
         obj.addProperty(
@@ -78,7 +78,7 @@ class _FemElementGeometry1D:
             "List of beam section shapes"
         )
         obj.SectionType = _FemElementGeometry1D.known_beam_types
-        obj.SectionType = 'Rectangular'
+        obj.SectionType = "Rectangular"
         obj.Proxy = self
         self.Type = "Fem::FemElementGeometry1D"
 

src/Mod/Fem/femobjects/_FemMaterial.py

@@ -44,7 +44,7 @@ class _FemMaterial:
             "Material",
             "Material type: fluid or solid"
         )
-        obj.Category = ['Solid', 'Fluid']  # used in TaskPanel
+        obj.Category = ["Solid", "Fluid"]  # used in TaskPanel
         obj.Proxy = self
         self.Type = "Fem::Material"
 

src/Mod/Fem/femobjects/_FemMaterialReinforced.py

@@ -50,8 +50,8 @@ class _FemMaterialReinforced:
             "Material",
             "Matrix material properties"
         )
-        obj.Category = ['Solid']
-        obj.Category = 'Solid'
+        obj.Category = ["Solid"]
+        obj.Category = "Solid"
         obj.Proxy = self
         self.Type = "Fem::MaterialReinforced"
 

src/Mod/Fem/femobjects/_FemMeshGmsh.py

@@ -34,25 +34,25 @@ class _FemMeshGmsh():
     """
 
     # they will be used from the task panel too, thus they need to be outside of the __init__
-    known_element_dimensions = ['From Shape', '1D', '2D', '3D']
-    known_element_orders = ['1st', '2nd']
+    known_element_dimensions = ["From Shape", "1D", "2D", "3D"]
+    known_element_orders = ["1st", "2nd"]
     known_mesh_algorithm_2D = [
-        'Automatic',
-        'MeshAdapt',
-        'Delaunay',
-        'Frontal',
-        'BAMG',
-        'DelQuad'
+        "Automatic",
+        "MeshAdapt",
+        "Delaunay",
+        "Frontal",
+        "BAMG",
+        "DelQuad"
     ]
     known_mesh_algorithm_3D = [
-        'Automatic',
-        'Delaunay',
-        'New Delaunay',
-        'Frontal',
-        'Frontal Delaunay',
-        'Frontal Hex',
-        'MMG3D',
-        'R-tree'
+        "Automatic",
+        "Delaunay",
+        "New Delaunay",
+        "Frontal",
+        "Frontal Delaunay",
+        "Frontal Hex",
+        "MMG3D",
+        "R-tree"
     ]
 
     def __init__(self, obj):
@@ -115,7 +115,7 @@ class _FemMeshGmsh():
             "Dimension of mesh elements (Auto = according ShapeType of part to mesh)"
         )
         obj.ElementDimension = _FemMeshGmsh.known_element_dimensions
-        obj.ElementDimension = 'From Shape'  # according ShapeType of Part to mesh
+        obj.ElementDimension = "From Shape"  # according ShapeType of Part to mesh
 
         obj.addProperty(
             "App::PropertyEnumeration",
@@ -124,7 +124,7 @@ class _FemMeshGmsh():
             "Order of mesh elements"
         )
         obj.ElementOrder = _FemMeshGmsh.known_element_orders
-        obj.ElementOrder = '2nd'
+        obj.ElementOrder = "2nd"
 
         obj.addProperty(
             "App::PropertyBool",
@@ -181,7 +181,7 @@ class _FemMeshGmsh():
             "mesh algorithm 2D"
         )
         obj.Algorithm2D = _FemMeshGmsh.known_mesh_algorithm_2D
-        obj.Algorithm2D = 'Automatic'  # ?
+        obj.Algorithm2D = "Automatic"  # ?
 
         obj.addProperty(
             "App::PropertyEnumeration",
@@ -190,7 +190,7 @@ class _FemMeshGmsh():
             "mesh algorithm 3D"
         )
         obj.Algorithm3D = _FemMeshGmsh.known_mesh_algorithm_3D
-        obj.Algorithm3D = 'Automatic'  # ?
+        obj.Algorithm3D = "Automatic"  # ?
 
         obj.addProperty(
             "App::PropertyBool",

src/Mod/Fem/femobjects/_FemSolverCalculix.py

@@ -174,47 +174,47 @@ class _FemSolverCalculix():
 
         ccx_default_time_incrementation_control_parameter = {
             # iteration parameter
-            'I_0': 4,
-            'I_R': 8,
-            'I_P': 9,
-            'I_C': 200,  # ccx default = 16
-            'I_L': 10,
-            'I_G': 400,  # ccx default = 4
-            'I_S': None,
-            'I_A': 200,  # ccx default = 5
-            'I_J': None,
-            'I_T': None,
+            "I_0": 4,
+            "I_R": 8,
+            "I_P": 9,
+            "I_C": 200,  # ccx default = 16
+            "I_L": 10,
+            "I_G": 400,  # ccx default = 4
+            "I_S": None,
+            "I_A": 200,  # ccx default = 5
+            "I_J": None,
+            "I_T": None,
             # cutback parameter
-            'D_f': 0.25,
-            'D_C': 0.5,
-            'D_B': 0.75,
-            'D_A': 0.85,
-            'D_S': None,
-            'D_H': None,
-            'D_D': 1.5,
-            'W_G': None}
+            "D_f": 0.25,
+            "D_C": 0.5,
+            "D_B": 0.75,
+            "D_A": 0.85,
+            "D_S": None,
+            "D_H": None,
+            "D_D": 1.5,
+            "W_G": None}
         p = ccx_default_time_incrementation_control_parameter
-        p_iter = '{0},{1},{2},{3},{4},{5},{6},{7},{8},{9}'.format(
-            p['I_0'],
-            p['I_R'],
-            p['I_P'],
-            p['I_C'],
-            p['I_L'],
-            p['I_G'],
-            '',
-            p['I_A'],
-            '',
-            ''
+        p_iter = "{0},{1},{2},{3},{4},{5},{6},{7},{8},{9}".format(
+            p["I_0"],
+            p["I_R"],
+            p["I_P"],
+            p["I_C"],
+            p["I_L"],
+            p["I_G"],
+            "",
+            p["I_A"],
+            "",
+            ""
         )
-        p_cutb = '{0},{1},{2},{3},{4},{5},{6},{7}'.format(
-            p['D_f'],
-            p['D_C'],
-            p['D_B'],
-            p['D_A'],
-            '',
-            '',
-            p['D_D'],
-            ''
+        p_cutb = "{0},{1},{2},{3},{4},{5},{6},{7}".format(
+            p["D_f"],
+            p["D_C"],
+            p["D_B"],
+            p["D_A"],
+            "",
+            "",
+            p["D_D"],
+            ""
         )
         obj.addProperty(
             "App::PropertyString",