PDT: Refactor - Stage 3 (Pylint & Black runs)

Most of the recommendations from pylint are now done, I have not changed variables
like v in expression [v for v in... as I consider these to be normal coding practice.

Rename pdt_com_functions.py to pdt_command_functions.py

Fix error in Intersect operation if selected vertices resulted in more than
2 edges being selected. Priority is given to two edges as a selection, then to
4 vertices, if the four vertices represent two edges, the intersection point is
at the intersection of the two edges, which might not be the four vertices, if
one of the vertices forms part of two edges that are also selected.

Priority is 2 edges, then 4 vertices selected individually with the mouse.

1 files changed, 76 insertions, 38 deletions

diff --git a/precision_drawing_tools/pdt_command.py b/precision_drawing_tools/pdt_command.py
index 8013a38a..5b6b1b51 100644
--- a/precision_drawing_tools/pdt_command.py
+++ b/precision_drawing_tools/pdt_command.py
@@ -32,7 +32,7 @@ from .pdt_functions import (
     oops,
     update_sel,
 )
-from .pdt_com_functions import (
+from .pdt_command_functions import (
     command_maths,
     vector_build,
     move_cursor_pivot,
@@ -194,37 +194,37 @@ def command_run(self, context):
     elif command == "":
         return
     elif command.upper() == "J2V":
-        join_two_vertices(self, context)
+        join_two_vertices(context)
         return
     elif command.upper() == "AD2":
-        set_angle_distance_two(self, context)
+        set_angle_distance_two(context)
         return
     elif command.upper() == "AD3":
-        set_angle_distance_three(self, context)
+        set_angle_distance_three(context)
         return
     elif command.upper() == "OTC":
-        origin_to_cursor(self, context)
+        origin_to_cursor(context)
         return
     elif command.upper() == "TAP":
         taper(self, context)
         return
     elif command.upper() == "BIS":
-        add_line_to_bisection(self, context)
+        add_line_to_bisection(context)
         return
     elif command.upper() == "ETF":
         extend_vertex(self, context)
         return
     elif command.upper() == "INTALL":
-        intersect_all(self, context)
+        intersect_all(context)
         return
     elif command.upper()[1:4] == "NML":
-        placement_normal(self, context, command.upper()[0])
+        placement_normal(context, command.upper()[0])
         return
     elif command.upper()[1:4] == "CEN":
-        placement_centre(self, context, command.upper()[0])
+        placement_centre(context, command.upper()[0])
         return
     elif command.upper()[1:4] == "INT":
-        placement_intersect(self, context, command.upper()[0])
+        placement_intersect(context, command.upper()[0])
         return
     elif len(command) < 3:
         pg.error = PDT_ERR_CHARS_NUM
@@ -262,7 +262,7 @@ def command_run(self, context):
     # --------------
     # Maths Operation
     if operation == "M":
-        command_maths(self, context, pg, command[2:], mode)
+        command_maths(context, mode, pg, command[2:], mode)
         return
 
     # -----------------------------------------------------
@@ -309,16 +309,16 @@ def command_run(self, context):
     if operation in {"C", "P"}:
         # Absolute/Global Coordinates, or Delta/Relative Coordinates
         if mode in {"a", "d"}:
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
         # Direction/Polar Coordinates
         elif mode == "i":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 2)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 2)
         # Percent Options
         elif mode == "p":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 1)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 1)
 
-        if vector_delta is not None:
-            move_cursor_pivot(self, context, pg, obj, verts, operation,
+        if valid_result:
+            move_cursor_pivot(context, pg, obj, verts, operation,
                 mode, vector_delta)
         return
 
@@ -332,7 +332,9 @@ def command_run(self, context):
                 return
         # Absolute/Global Coordinates
         if mode == "a":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
             if obj.mode == "EDIT":
                 for v in verts:
                     v.co = vector_delta - obj_loc
@@ -346,10 +348,14 @@ def command_run(self, context):
         elif mode in {"d", "i"}:
             if mode == "d":
                 # Delta/Relative Coordinates
-                vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+                valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+                if not valid_result:
+                    return
             else:
                 # Direction/Polar Coordinates
-                vector_delta = vector_build(self, context, pg, obj, operation, values, 2)
+                valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 2)
+                if not valid_result:
+                    return
             if vector_delta is not None:
                 if obj.mode == "EDIT":
                     bmesh.ops.translate(
@@ -360,7 +366,9 @@ def command_run(self, context):
                         ob.location = obj_loc + vector_delta
         # Percent Options
         elif mode == "p":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 1)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 1)
+            if not valid_result:
+                return
             if vector_delta is not None:
                 if obj.mode == 'EDIT':
                     verts[-1].co = vector_delta
@@ -380,19 +388,27 @@ def command_run(self, context):
             return
         # Absolute/Global Coordinates
         if mode == "a":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
             new_vertex = bm.verts.new(vector_delta - obj_loc)
         # Delta/Relative Coordinates
         elif mode == "d":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
             new_vertex = bm.verts.new(verts[-1].co + vector_delta)
         # Direction/Polar Coordinates
         elif mode == "i":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 2)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 2)
+            if not valid_result:
+                return
             new_vertex = bm.verts.new(verts[-1].co + vector_delta)
         # Percent Options
         elif mode == "p":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 1)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 1)
+            if not valid_result:
+                return
             new_vertex = bm.verts.new(vector_delta)
 
         for v in [v for v in bm.verts if v.select]:
@@ -411,7 +427,9 @@ def command_run(self, context):
             return
         # Absolute/Global Coordinates
         if mode == "a":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
             edges = [e for e in bm.edges if e.select]
             if len(edges) != 1:
                 pg.error = f"{PDT_ERR_SEL_1_EDGE} {len(edges)})"
@@ -423,7 +441,9 @@ def command_run(self, context):
             new_vertex.co = vector_delta - obj_loc
         # Delta/Relative Coordinates
         elif mode == "d":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
             edges = [e for e in bm.edges if e.select]
             faces = [f for f in bm.faces if f.select]
             if len(faces) != 0:
@@ -439,7 +459,9 @@ def command_run(self, context):
             bmesh.ops.translate(bm, verts=new_verts, vec=vector_delta)
         # Directional/Polar Coordinates
         elif mode == "i":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 2)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 2)
+            if not valid_result:
+                return
             edges = [e for e in bm.edges if e.select]
             faces = [f for f in bm.faces if f.select]
             if len(faces) != 0:
@@ -455,8 +477,8 @@ def command_run(self, context):
             bmesh.ops.translate(bm, verts=new_verts, vec=vector_delta)
         # Percent Options
         elif mode == "p":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 1)
-            if vector_delta is None:
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 1)
+            if not valid_result:
                 return
             edges = [e for e in bm.edges if e.select]
             faces = [f for f in bm.faces if f.select]
@@ -464,7 +486,7 @@ def command_run(self, context):
                 pg.error = PDT_ERR_FACE_SEL
                 context.window_manager.popup_menu(oops, title="Error", icon="ERROR")
                 return
-            if len(edges) < 1:
+            if len(edges) != 1:
                 pg.error = f"{PDT_ERR_SEL_1_EDGEM} {len(edges)})"
                 context.window_manager.popup_menu(oops, title="Error", icon="ERROR")
                 return
@@ -490,7 +512,9 @@ def command_run(self, context):
             return
         # Absolute/Global Coordinates
         if mode == "a":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
             new_vertex = bm.verts.new(vector_delta - obj_loc)
             for v in verts:
                 bm.edges.new([v, new_vertex])
@@ -501,7 +525,9 @@ def command_run(self, context):
             )
         # Delta/Relative Coordinates
         elif mode == "d":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
             for v in verts:
                 new_vertex = bm.verts.new(v.co)
                 new_vertex.co = new_vertex.co + vector_delta
@@ -510,7 +536,9 @@ def command_run(self, context):
                 new_vertex.select_set(True)
         # Direction/Polar Coordinates
         elif mode == "i":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 2)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 2)
+            if not valid_result:
+                return
             for v in verts:
                 new_vertex = bm.verts.new(v.co)
                 new_vertex.co = new_vertex.co + vector_delta
@@ -519,7 +547,9 @@ def command_run(self, context):
                 new_vertex.select_set(True)
         # Percent Options
         elif mode == "p":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 1)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 1)
+            if not valid_result:
+                return
             verts = [v for v in bm.verts if v.select].copy()
             if len(verts) == 0:
                 pg.error = PDT_ERR_NO_SEL_GEOM
@@ -547,10 +577,14 @@ def command_run(self, context):
             return
         # Delta/Relative Coordinates
         if mode == "d":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
         # Direction/Polar Coordinates
         elif mode == "i":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 2)
+            valid_result, vector_delta = vector_build(context, pg, obj, values, 2)
+            if not valid_result:
+                return
 
         ret = bmesh.ops.extrude_face_region(
             bm,
@@ -581,10 +615,14 @@ def command_run(self, context):
             return
         # Delta/Relative Coordinates
         if mode == "d":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 3)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 3)
+            if not valid_result:
+                return
         # Direction/Polar Coordinates
         elif mode == "i":
-            vector_delta = vector_build(self, context, pg, obj, operation, values, 2)
+            valid_result, vector_delta = vector_build(context, pg, obj, operation, values, 2)
+            if not valid_result:
+                return
 
         ret = bmesh.ops.duplicate(
             bm,