Stack application bracket matching problem (Python version)

Stack application bracket matching problem (Python version)

Check if parentheses are closed

• Sequential scan is checked for characters in the body (one character)
• Skip extraneous characters in check (all non-bracket characters are not related to current processing)
• The opening parenthesis is encountered to press it into the stack
• The top element of the stack pops up when closing parentheses are encountered
• If the match succeeds then continue, and the match fails to check for failure to end

1 defcheck_parens (text):2     #parentheses Match Check function, text is checked body string3Parens ="(){}[]"4Open_parens ="({["5opposite = {")":"(","}":"{","]":"["}6     7     defparentheses (text):8         #parenthesis Generator, each call returns the next parenthesis in text and its position9I.text_len =0,len (text)Ten          whileTrue: One              whileI < Text_len andText[i] not inchparens: Ai + = 1 -             ifI >=Text_len: -                 return the             yieldText[i],i -i + = 1 -  -st = Sstack ()#Create Stack St +  -      forPR, I parentheses (text):#iterate over parentheses and positions in text +         ifprinchOpen_parens:#open brackets, press stack and continue A St.push (PR) at         elifSt.pop ()! = OPPOSITE[PR]:#close parenthesis Exit if match fails -             Print("unmatching is found at"I" for", PR) -             returnFalse -         Else:#the match succeeds and does nothing. -             

Stack application bracket matching problem (Python version)