import re STRING='(\'[^\']*\')|("(.[^"])*")' """ re.match(STRING, '"AJAY"') re.match(STRING, "'AJAY'") """ ID='[a-zA-Z_][a-z0-9A-Z_]*' """ re.match(ID, "AB") re.match(ID, "__") re.match(ID, "__123") re.match(ID, "aa") re.match(ID, "_a") re.match(ID, "a_") re.match(ID, "__") """ INT='\d+' """ re.match(INT, "12") re.match(INT, "123") re.match(INT, "1234") """ FLOAT='\\d+\\.\\d+' """ re.match('\\d+\\.\\d+', "1.123") re.match('\\d+\\.\\d+', "1234.123") re.match('\\d+\\.\\d+', "1.0") """ QUALIFIER='(static|global)?' """ re.match(QUALIFIER,"static") re.match(QUALIFIER,"global") re.match(QUALIFIER,"") """ SECURITY='(public|private|protected)?' """ re.match(SECURITY,"public") re.match(SECURITY,"private") re.match(SECURITY,"protected") re.match(SECURITY,"") """ #OP='(\\+|-|*|/|%|^)' OP='(\\+|-|\*|/|%|\^)' """ re.match('(\\+|-|\*|/|%|^)+',"+") re.match('(\\+|-|\*|/|%|^)+',"-") re.match('(\\+|-|\*|/|%|^)+',"*") re.match('(\\+|-|\*|/|%|^)+',"/") re.match('(\\+|-|\*|/|%|^)+',"%") re.match('(\\+|-|\*|/|%|^)+',"^") re.match('(\\+|-|\*|/|%|\^)+',"^") """ #EXP='(('+STRING+'|'+ID+')((\\s)?('+STRING+'|'+ID+'))*|((('+INT+'|'+FLOAT+'|'+ID+')('+OP+'('+INT+'|'+ID+'|'+FLOAT+'))*' EXP='(('+STRING+'|'+ID+')((\\s)?('+STRING+'|'+ID+'))*|(('+INT+'|'+FLOAT+'|'+ID+')('+OP+'('+INT+'|'+ID+'|'+FLOAT+'))*))' ASSIGN='('+OP+')?=' STMT='\\s'+SECURITY+'\\s*'+QUALIFIER+'\\s*'+ASSIGN+'\\s*'+EXP+'\\s*' if __name__ == '__main__': print(re.match(STMT,"The Great Saga"))

regex_problem_vishal_gupta.py