使用Python为文本编辑器添加语法高亮
我正在创建一个自己的基于网页的文本编辑器，我想加入语法高亮功能。开始的时候我会先为一种语言（可能是Python）做高亮，之后我想为我能想到的所有语言都添加高亮。
如果可能的话，我想找一个相关的教程，有人知道哪里可以找到吗？
另外，如果你有其他的建议也非常欢迎。
3 个回答
1
在编程中，有时候我们会遇到一些问题，特别是在使用某些工具或库的时候。这些问题可能会让我们感到困惑，不知道该如何解决。比如，有人可能在使用某个功能时，发现它没有按照预期工作，或者出现了错误信息。这种时候，查看相关的讨论或者提问是很有帮助的。
在社区网站上，比如StackOverflow，很多人会分享他们遇到的问题和解决方案。你可以在这里找到很多有用的信息，帮助你理解问题的根源，以及如何修复它们。
总之，遇到问题时，不要害怕去寻求帮助，看看别人是怎么解决类似问题的，这样你也能学到很多东西。
# syntax.py
import sys
from PyQt4.QtCore import QRegExp
from PyQt4.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 = expression.cap(nth).length()
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 = text.length() - 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
1
在编程中，有时候我们会遇到一些问题，像是代码运行不正常或者出现错误。这时候，我们可以在网上寻找帮助，比如在StackOverflow这个网站上。这个网站上有很多程序员分享他们的经验和解决方案。
当你在StackOverflow上提问时，记得要描述清楚你的问题，包括你遇到的错误信息、你使用的代码，以及你希望实现的目标。这样其他人才能更好地理解你的问题，并给出有效的建议。
同时，查看别人提问的内容也很有帮助，因为你可能会发现和自己遇到的问题类似的情况。通过阅读这些问题和答案，你可以学到很多解决问题的方法和技巧。
总之，StackOverflow是一个很好的学习和解决问题的地方，只要你善于利用它，就能提高自己的编程能力。
from PyQt4 import QtGui
import syntax
app = QtGui.QApplication([])
texter = QtGui.QPlainTextEdit()
highlight = syntax.PythonHighlighter(texter.document())
texter.show()
infile = open('syntax.py', 'r')
texter.setPlainText(infile.read())
app.exec_()
#use the program syntax.py to make it work I posted it
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