在pyqt5中使用QSyntaxHighlighter突出显示语法

from PyQt5.QtGui import QTextDocument, QTextCharFormat, QFont, QColor
from PyQt5.QtWidgets import QApplication, QMainWindow, QTextEdit
from PyQt5.QtCore import Qt, QRegExp
from PyQt5.QtSyntaxHighlighter import QSyntaxHighlighter, QRegularExpressionValidator

class Highlighter(QSyntaxHighlighter):
    def __init__(self, parent=None):
        super(Highlighter, self).__init__(parent)

    def highlightBlock(self, text):
        # 定义关键字的格式
        keywordFormat = QTextCharFormat()
        keywordFormat.setForeground(Qt.darkBlue)
        keywordFormat.setFontWeight(QFont.Bold)

        # 定义注释的格式
        commentFormat = QTextCharFormat()
        commentFormat.setForeground(Qt.darkGreen)

        # 定义字符串的格式
        stringFormat = QTextCharFormat()
        stringFormat.setForeground(Qt.darkRed)

        # 定义正则表达式匹配规则
        rules = [
            (QRegExp("\\bint\\b"), keywordFormat),
            (QRegExp("\\bfloat\\b"), keywordFormat),
            (QRegExp("\\bstring\\b"), keywordFormat),
            (QRegExp("#.*"), commentFormat),
            (QRegExp("\".*\""), stringFormat)
        ]

        # 对文本块应用匹配规则
        for pattern, format in rules:
            expression = QRegExp(pattern)
            index = expression.indexIn(text)
            while index >= 0:
                length = expression.matchedLength()
                self.setFormat(index, length, format)
                index = expression.indexIn(text, index + length)

class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()

        self.textEdit = QTextEdit()
        self.setCentralWidget(self.textEdit)

        self.highlighter = Highlighter(self.textEdit.document())