from PyQt5.QtCore import QRegExp from PyQt5.QtGui import QColor, QTextCharFormat, QFont, QSyntaxHighlighter def format(color, style=''): """Return a QTextCharFormat with the given attributes. """ _color = QColor() _color.setNamedColor(color) _format = QTextCharFormat() _format.setForeground(_color) if 'bold' in style: _format.setFontWeight(QFont.Bold) if 'italic' in style: _format.setFontItalic(True) return _format # Syntax styles that can be shared by all languages STYLES = { 'keyword': format('blue'), 'operator': format('red'), 'brace': format('darkGray'), 'defclass': format('black', 'bold'), 'string': format('magenta'), 'string2': format('darkMagenta'), 'comment': format('darkGreen', 'italic'), 'self': format('black', 'italic'), 'numbers': format('brown'), } class PythonHighlighter (QSyntaxHighlighter): """Syntax highlighter for the Python language. """ # Python keywords keywords = [ 'and', 'assert', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'exec', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'not', 'or', 'pass', 'print', 'raise', 'return', 'try', 'while', 'yield', 'None', 'True', 'False', ] # Python operators operators = [ '=', # Comparison '==', '!=', '<', '<=', '>', '>=', # Arithmetic '\+', '-', '\*', '/', '//', '\%', '\*\*', # In-place '\+=', '-=', '\*=', '/=', '\%=', # Bitwise '\^', '\|', '\&', '\~', '>>', '<<', ] # Python braces braces = [ '\{', '\}', '\(', '\)', '\[', '\]', ] def __init__(self, document): QSyntaxHighlighter.__init__(self, document) # Multi-line strings (expression, flag, style) # FIXME: The triple-quotes in these two lines will mess up the # syntax highlighting from this point onward self.tri_single = (QRegExp("'''"), 1, STYLES['string2']) self.tri_double = (QRegExp('"""'), 2, STYLES['string2']) rules = [] # Keyword, operator, and brace rules rules += [(r'\b%s\b' % w, 0, STYLES['keyword']) for w in PythonHighlighter.keywords] rules += [(r'%s' % o, 0, STYLES['operator']) for o in PythonHighlighter.operators] rules += [(r'%s' % b, 0, STYLES['brace']) for b in PythonHighlighter.braces] # All other rules rules += [ # 'self' (r'\bself\b', 0, STYLES['self']), # Double-quoted string, possibly containing escape sequences (r'"[^"\\]*(\\.[^"\\]*)*"', 0, STYLES['string']), # Single-quoted string, possibly containing escape sequences (r"'[^'\\]*(\\.[^'\\]*)*'", 0, STYLES['string']), # 'def' followed by an identifier (r'\bdef\b\s*(\w+)', 1, STYLES['defclass']), # 'class' followed by an identifier (r'\bclass\b\s*(\w+)', 1, STYLES['defclass']), # From '#' until a newline (r'#[^\n]*', 0, STYLES['comment']), # Numeric literals (r'\b[+-]?[0-9]+[lL]?\b', 0, STYLES['numbers']), (r'\b[+-]?0[xX][0-9A-Fa-f]+[lL]?\b', 0, STYLES['numbers']), (r'\b[+-]?[0-9]+(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\b', 0, STYLES['numbers']), ] # Build a QRegExp for each pattern self.rules = [(QRegExp(pat), index, fmt) for (pat, index, fmt) in rules] def highlightBlock(self, text): """Apply syntax highlighting to the given block of text. """ # Do other syntax formatting for expression, nth, format in self.rules: index = expression.indexIn(text, 0) while index >= 0: # We actually want the index of the nth match index = expression.pos(nth) length = len(expression.cap(nth)) self.setFormat(index, length, format) index = expression.indexIn(text, index + length) self.setCurrentBlockState(0) # Do multi-line strings in_multiline = self.match_multiline(text, *self.tri_single) if not in_multiline: in_multiline = self.match_multiline(text, *self.tri_double) def match_multiline(self, text, delimiter, in_state, style): """Do highlighting of multi-line strings. ``delimiter`` should be a ``QRegExp`` for triple-single-quotes or triple-double-quotes, and ``in_state`` should be a unique integer to represent the corresponding state changes when inside those strings. Returns True if we're still inside a multi-line string when this function is finished. """ # If inside triple-single quotes, start at 0 if self.previousBlockState() == in_state: start = 0 add = 0 # Otherwise, look for the delimiter on this line else: start = delimiter.indexIn(text) # Move past this match add = delimiter.matchedLength() # As long as there's a delimiter match on this line... while start >= 0: # Look for the ending delimiter end = delimiter.indexIn(text, start + add) # Ending delimiter on this line? if end >= add: length = end - start + add + delimiter.matchedLength() self.setCurrentBlockState(0) # No; multi-line string else: self.setCurrentBlockState(in_state) length = len(text) - start + add # Apply formatting self.setFormat(start, length, style) # Look for the next match start = delimiter.indexIn(text, start + length) # Return True if still inside a multi-line string, False otherwise if self.currentBlockState() == in_state: return True else: return False if __name__ == '__main__': from PyQt5 import QtWidgets app = QtWidgets.QApplication([]) editor = QtWidgets.QPlainTextEdit() highlight = PythonHighlighter(editor.document()) editor.show() # Load syntax.py into the editor for demo purposes infile = open('PythonSyntax.py', 'r') editor.setPlainText(infile.read()) app.exec_()