LearnRegexPyQt5.py

# Python Regular Expressions - GUI Interactive Tool  
#   Chandra Lingam
#   http://c2designs.cloud
#   
#   Compatible with 3.x version of python
# Distributed under GNU Public License - https://www.gnu.org/licenses/gpl-3.0.en.html

# Version History
# Original Version - Chandra Lingam
# PyQt5 migration - Sash Eranki

import sys
from PyQt5 import QtGui, QtWidgets  #modified from PyQt4 to PyQt5 for anaconda 3.5 distr
import re
import time

class LearnRegex(QtWidgets.QWidget):
    
    def __init__(self):
        super(LearnRegex, self).__init__()
        
        self.init_ui()
        
    def init_ui(self):
        self.setFont(QtGui.QFont("Sans Serif", 11))
        self.txtPattern = QtWidgets.QLineEdit()
        self.txtRepPattern = QtWidgets.QLineEdit()
        # Changed to plain text
        self.txtText= QtWidgets.QPlainTextEdit()
        self.txtResult = QtWidgets.QTextEdit()
        
        self.regex = None
        self.regexText = None        
        lblPattern = QtWidgets.QLabel('Pattern')
        lblRepPattern = QtWidgets.QLabel('Replacement Pattern')
        lblText = QtWidgets.QLabel('Text')
        lblResult = QtWidgets.QLabel('Result')
        btnMatch = QtWidgets.QPushButton('Match')
        btnNextMatch = QtWidgets.QPushButton('Next Match')
        btnReplace = QtWidgets.QPushButton('Replace')
        btnSplit = QtWidgets.QPushButton('Split')
    
        btnMatch.clicked.connect(self.match_click)
        btnNextMatch.clicked.connect(self.next_match_click)
        btnReplace.clicked.connect(self.replace_click)
        btnSplit.clicked.connect(self.split_click)
                                
        grid = QtWidgets.QGridLayout()
        grid.setSpacing(10)
        grid.addWidget(lblPattern, 1, 0)
        grid.addWidget(self.txtPattern, 1, 1, 1, 4)
        grid.addWidget(lblRepPattern, 2, 0)
        grid.addWidget(self.txtRepPattern, 2, 1, 1, 4)
        
        grid.addWidget(lblText, 3, 0)
        grid.addWidget(self.txtText, 3, 1, 1, 4)
        grid.addWidget(btnMatch, 4, 1)
        grid.addWidget(btnNextMatch, 4, 2)
        grid.addWidget(btnReplace, 4, 3)
        grid.addWidget(btnSplit, 4, 4)                        
        grid.addWidget(lblResult, 5, 0)
        grid.addWidget(self.txtResult, 5, 1, 5, 4)
        
        self.setLayout(grid) 
        
        self.setGeometry(300, 300, 860, 620)
        self.setWindowTitle('Learning Regex with Python')    
        self.show()
        
        
    def match_click(self):
        self.txtResult.setText ('Value,Index,Length,ElapsedTime(s)')
        try:
            self.regex = re.compile(self.txtPattern.text())
        except Exception as e:           
            QtWidgets.QMessageBox.critical(self, 'Error', 'Pattern error: {0}'.format(str(e)))
            return
            
        self.regex_text = self.txtText.toPlainText()
        self.regex_group_index = dict((v,k) for k,v in self.regex.groupindex.items())
        self.match_iter = self.regex.finditer(self.regex_text)
        self.highlight_match()
        
    def next_match_click(self):
        self.highlight_match()
        
    def replace_click(self):
        self.txtResult.setText(re.sub(self.txtPattern.text(), self.txtRepPattern.text(), self.txtText.toPlainText()))
                        
    def split_click(self):
        self.txtResult.setText("")
        for s in re.split(self.txtPattern.text(), self.txtText.toPlainText()):
            self.txtResult.append(s)
        
    def highlight_match(self):
        start_time = None
        try:
            #self.txtText.setAcceptRichText(False)            
            self.txtText.setPlainText(self.regex_text)
            
            start_time = time.time()
            match = self.match_iter.__next__()
            end_time = time.time()
            
            self.txtResult.append ('{0},{1},{2},{3:.2f}'.format(match.group(0),match.start(), match.end()-match.start(), end_time - start_time))
            
            for i in range(0, len(match.groups())):
                gn = i+1
                group_name = None
                if gn in self.regex_group_index:
                    group_name = self.regex_group_index[gn]
    
                self.txtResult.append ('  Group:{0}, Name:{1}, Value: {2}'.format(gn, group_name, match.group(gn)))
                
            self.highlighter(match.start(), match.end())
            
        except StopIteration:
            end_time = time.time()            
            self.txtResult.append ('End, Elapsed Time (s): {0:0.2f}'.format(end_time - start_time))                            
    def highlighter(self,start,end):
        format = QtGui.QTextCharFormat()
        format.setBackground(QtGui.QBrush(QtGui.QColor("yellow")))
        cursor = self.txtText.textCursor()
        cursor.setPosition(start)
        cursor.movePosition(QtGui.QTextCursor.Right,QtGui.QTextCursor.KeepAnchor,end-start)
        cursor.mergeCharFormat(format)            
        
def main():
    
    app = QtWidgets.QApplication(sys.argv)
    ex = LearnRegex()
    sys.exit(app.exec_())
if __name__ == '__main__':
    main()