[PyQt6] Add new file to migrate from 3 to 4

scripts/3to4/3to4.py

@@ -0,0 +1,175 @@
+#!/usr/bin/env python3
+
+"""
+***************************************************************************
+    3to4.py
+    ---------------------
+    Date                 : 2023 December
+    Copyright            : (C) 2023 by Julien Cabieces
+    Email                : julien dot cabieces at oslandia dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+"""
+Migrate a folder containing python files from QGIS3/Qt5 to QGIS4/Qt6
+
+Highly inspired from this video https://www.youtube.com/watch?v=G1omxo5pphw
+
+needed tools:
+pip install astpretty tokenize-rt
+
+Few usefull commands:
+
+- display python file ast
+astpretty --no-show-offsets myfile.py
+
+- display file tokens
+tokenize-rt myfile.py
+"""
+
+__author__ = 'Julien Cabieces'
+__date__ = '2023 December'
+__copyright__ = '(C) 2023, Julien Cabieces'
+
+
+import argparse
+import ast
+import glob
+import os
+
+from collections import defaultdict
+
+from tokenize_rt import Offset, src_to_tokens, tokens_to_src, reversed_enumerate, Token
+
+from typing import Sequence
+
+qmetatype_mapping = {"String": "QString",
+                     "Invalid": "UnknownType",
+                     "Date": "QDate",
+                     "Time": "QTime",
+                     "DateTime": "QDateTime",
+                     "ByteArray": "QByteArray",
+                     "StringList": "QStringList"
+                     }
+
+# key: class that has moved from one module to another
+# value: (qt5 module, qt6 module)
+moved_classes = {"QAction": ("QtWidgets", "QtGui")}
+
+NEW_LINE = Token('NEWLINE', '\n')
+SPACE = Token('UNIMPORTANT_WS', ' ')
+COMMA = Token('OP', ',')
+POINT = Token('OP', '.')
+
+
+def import_tokens(module, classes):
+    classes_str = ",".join(classes)
+    return src_to_tokens(f"from qgis.PyQt.{module} import {classes_str}")
+
+
+def fix_file(filename: str, args: argparse.Namespace) -> int:
+
+    if (filename != "../python/plugins/processing/gui/BatchInputSelectionPanel.py"):
+        return 0
+
+    with (open(filename, encoding='UTF-8') as f):
+        contents = f.read()
+
+    fix_qvariant_type = [] # QVariant.Int, QVariant.Double ...
+    fix_pyqt_import = [] # from PyQt5.QtXXX
+    fix_moved_classes = [] # classes changing from modules
+
+    new_import_qt5 = defaultdict(list)
+    new_import_qt6 = defaultdict(list)
+
+    last_import = None
+
+    tree = ast.parse(contents, filename=filename)
+    for node in ast.walk(tree):
+
+        if (isinstance(node, ast.ImportFrom)):
+            last_import = Offset(node.end_lineno, node.end_col_offset)
+
+        if (isinstance(node, ast.ImportFrom) and node.module in ["PyQt5.QtWidgets", "qgis.PyQt.QtWidgets", "PyQt5.QtGui", "qgis.PyQt.QtGui"]):
+            for name in node.names:
+                if name.name in moved_classes:
+                    fix_moved_classes.append(Offset(name.lineno, name.col_offset))
+                    new_import_qt5[moved_classes[name.name][0]].append(name.name)
+                    new_import_qt6[moved_classes[name.name][1]].append(name.name)
+
+        if (isinstance(node, ast.Attribute) and isinstance(node.value, ast.Name)
+                and node.value.id == "QVariant"):
+            fix_qvariant_type.append(Offset(node.lineno, node.col_offset))
+        elif (isinstance(node, ast.ImportFrom) and node.module.startswith("PyQt5.")):
+            fix_pyqt_import.append(Offset(node.lineno, node.col_offset))
+
+    if not fix_qvariant_type and not fix_pyqt_import and not fix_moved_classes:
+        return 0
+
+    tokens = src_to_tokens(contents)
+    for i, token in reversed_enumerate(tokens):
+        if token.offset in fix_qvariant_type:
+            assert tokens[i].src == "QVariant"
+            assert tokens[i + 1].src == "."
+            tokens[i] = tokens[i]._replace(src="QMetaType.Type")
+            attr = tokens[i + 2].src
+            if attr in qmetatype_mapping:
+                tokens[i + 2] = tokens[i + 2]._replace(src=qmetatype_mapping[attr])
+
+        if token.offset in fix_pyqt_import:
+            assert tokens[i + 2].src == "PyQt5"
+            tokens[i + 2] = tokens[i + 2]._replace(src="qgis.PyQt")
+
+        if token.offset in fix_moved_classes:
+            # TODO We need to deal with case where we have removed all imported classes
+            tokens[i] = tokens[i]._replace(src="")
+            j = i + 1
+            while tokens[j].src == "," or tokens[j].name == 'UNIMPORTANT_WS' or tokens[j].name == 'NEWLINE':
+                tokens[j] = tokens[j]._replace(src="")
+                j += 1
+
+        if token.offset == last_import:
+
+            new_tokens = [NEW_LINE] * 2 + import_tokens("QtCore", ["QT_VERSION"])
+            new_tokens += [NEW_LINE] + src_to_tokens("if (QT_VERSION >= 0x060000):") + [NEW_LINE]
+            for module, classes in new_import_qt6.items():
+                new_tokens += [Token('INDENT', '    ')] + import_tokens(module, classes)
+            new_tokens += [NEW_LINE] + src_to_tokens("else:") + [NEW_LINE]
+            for module, classes in new_import_qt5.items():
+                new_tokens += [Token('INDENT', '    ')] + import_tokens(module, classes)
+
+            for tok in reversed(new_tokens):
+                tokens.insert(i, tok)
+
+    new_contents = tokens_to_src(tokens)
+    with (open(filename, 'w') as f):
+        f.write(new_contents)
+
+    return new_contents != contents
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('directory')
+    # parser.add_argument('--exit-zero-even-if-changed', action='store_true')
+    # parser.add_argument('--py35-plus', action='store_true')
+    # parser.add_argument('--py36-plus', action='store_true')
+    args = parser.parse_args(argv)
+
+    print(os.path.join(args.directory, "*.py"))
+
+    ret = 0
+    for filename in glob.glob(os.path.join(args.directory, "*.py")):
+        ret |= fix_file(filename, args)
+    return ret
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())