I need help reviewing this code and making sure it reads from a file C programming language and it processes it through a lexical, sintaxis$,$ semantic analyzer and then it outputs an object file $.$o with code transformed to assembly code. import pandas as pd

LEXER$\_$TABLE $=$ pd$.$DataFrame$($columns $=[\text{'}$TOKEN$\text{'},$'IDENTITY'$],$ index $=$ range$(1))$

def lexer$($code$)$:

SYMBOLS $=[\text{'}(\text{'},\text{'})\text{'},\text{'}$;$\text{'},\text{'},\text{'},\text{'}$:$\text{'},"\text{'}"]$

SYMBOLS$\_1=[\text{'}(\text{'},\text{'})\text{'},\text{'}$;$\text{'},\text{'},\text{'},\text{'}$:$\text{'},"\text{'}",\text{'}+\text{'},\text{'}=\text{'},\text{'}>\text{'}]$

SYMBOLS$\_1\_$DUP $=[$

$[\text{'}$Open bracket', $\text{'}(\text{'}],$

$[\text{'}$close bracket', $\text{'})\text{'}],$

$[\text{'}$semicolon$\text{'},\text{'}$;$\text{'}],$

$[\text{'}$comma$\text{'},\text{'},\text{'}],$

$[\text{'}$colon$\text{'},\text{'}$:$\text{'}],$

$[\text{'}$single quote', $"\text{'}"],$

$[\text{'}$plus$\text{'},\text{'}+\text{'}],$

$[\text{'}$equal$\text{'},\text{'}=\text{'}],$

$[\text{'}$greater than', $\text{'}>\text{'}]$

$]$

keywords $=[\text{'}$integers$\text{'},$ 'main', 'while', 'begin', 'end', 'expr', 'procedure', $\text{'}$If$\text{'},$ 'elseif', 'else', 'then', 'printf', 'and', $\text{'}$or$\text{'}]$

KEYWORDS $=$ SYMBOLS$\_1+$ keywords

white$\_$space $=\text{'}\text{'}$

lexeme $=\text{'}\text{'}$

tokens $=[]$

code $=$ code.replace$(\text{'}\backslash$t$\text{'},\text{'}\text{'})$

for i$,$ char in enumerate$($code$)$:

if char $!=$ white$\_$space:

lexeme $+=$ char

if $($i$+1<$ len$($code$))$:

if code$[$i$+1]==$ white$\_$space or code$[$i $+1]$ in KEYWORDS or lexeme in KEYWORDS:

if lexeme $!=\text{'}\text{'}$:

tokens.append$($lexeme$.$replace$(\text{'}\text{'},\text{'}\text{'}))$

lexeme $=\text{'}\text{'}$

j $=0$

for i in tokens:

for k in SYMBOLS$\_1\_$DUP:

if i $==$ k$[1]$:

LEXER$\_$TABLE.at$[$j$,$ 'TOKEN'$]=$ i

LEXER$\_$TABLE.at$[$j$,$ 'IDENTITY'$]=$ k$[0]$

j $+=1$

break

if i in keywords:

LEXER$\_$TABLE.at$[$j$,$ 'TOKEN'$]=$ i

LEXER$\_$TABLE.at$[$j$,$ 'IDENTITY'$]=$ 'keyword'

j $+=1$

continue

if i$.$isdigit$()$:

LEXER$\_$TABLE.at$[$j$,$ 'TOKEN'$]=$ i

LEXER$\_$TABLE.at$[$j$,$ 'IDENTITY'$]=$ 'Digit'

j $+=1$

continue

elif i not in KEYWORDS:

LEXER$\_$TABLE.at$[$j$,$ 'TOKEN'$]=$ i

LEXER$\_$TABLE.at$[$j$,$ 'IDENTITY'$]=$ 'Identifier'

j $+=1$

continue

print$($f$"$Lexer Tokens: $\{$tokens$\}")$

return tokens

if $\_\_$name$\_\_=="\_\_$main$\_\_"$:

code $="3+5*(10-20)"$

tokens $=$ lexer$($code$)$

print$("$tokens:$",$ tokens$)$

class Node:

def $\_\_$init$\_\_($self$,$ type, value $=$ None$)$:

self.type $=$ type

self.value $=$ value

self.children $=[]$

def add$\_$child$($self$,$node$)$:

self.children.append$($node$)$

class Parser:

def $\_\_$init$\_\_($self$,$ tokens$)$:

self.tokens $=$ tokens

self.current$\_$token$\_$index $=0$

def parse$($self$)$:

return self.expr$()$

def expr$($self$)$:

node $=$ self.term$()$

while self.current$\_$token$()$ in $[\text{'}+\text{'},\text{'}-\text{'}]$:

token $=$ self.current$\_$token$()$

self.eat$($token$)$

node $=$ Node$($type $=$ token, value $=$ token$)$

node.add$\_$child$($self$.$term$())$

return node

def term$($self$)$:

node $=$ self.factor$()$

while self.current$\_$token$()$ in $[\text{'}*\text{'},\text{'}/\text{'}]$:

token $=$ self.current.token$()$

self.eat$($token$)$

node $=$ Node$($type $=$ token, value $=$ token$)$

node.add$\_$child$($self$.$factor$())$

return node

def factor$($self$)$:

token $=$ self.current$\_$token$()$

if token.isdigit$()$:

self.eat$($token$)$

return Node$($type $=$ 'NUMBER', value $=$ int$($token$))$

elif token $==\text{'}(\text{'}$:

self.eat$(\text{'}(\text{'})$

node $=$ self.expr$()$

self.eat$(\text{'})\text{'})$

return node

def current$\_$token$($self$)$:

return self.tokens$[$self$.$current$\_$token$\_$index$]$

def eat$($self$,$token$\_$type$)$:

if self.current$\_$token$()==$ token$\_$type:

self.current$\_$token$\_$index $+=1$

else:

raise Exception$($f$"$Unexpected token: $\{$self$.$current$\_$token$()\}")$

if $\_\_$name$\_\_=="\_\_$main$\_\_"$:

code $="3+5*(10-20)"$

tokens $=$ lexer$($code$)$

parser $=$ Parser$($tokens$)$

try:

ast $=$ parser.parse$()$

print$("$Parsed AST sucessfully"$)$

except Exception as e:

print$($f$"$parsing error: $\{$e$\}")$

class CodeGenerator:

def $\_\_$init$\_\_($self$,$ ast$)$:

self.ast $=$ ast

self.code $=[]$

self.temp$\_$count $=0$

def generate$\_$code$($self$)$:

self.visit$($self$.$ast$)$

return self.code

def visit$($self$,$ node$)$:

if node.type $==$ 'NUMBER':

self.code.append$($f$"$LOAD $\{$node$.$value$\}")$

elif node.type in $[\text{'}+\text{'},\text{'}-\text{'},\text{'}*\text{'},\text{'}/\text{'}]$:

left $=$ node.children$[0]$

self.visit$($left$)$

right $=$ node.children$[1]$

self.visit$($right$)$

self.code.append$($f$"\{$node$.$type$\}$ TEMP$\{$self$.$temp$\_$count$\}")$

self.temp$\_$count $+=1$

if $\_\_$name$\_\_=="\_\_$main$\_\_"$:

code $="3+5*(10-20)"$

tokens $=$ lexer$($code$)$

parser $=$ Parser$($tokens$)$

try:

ast $=$ parser.parse$()$

codegen $=$ CodeGenerator$($ast$)$

object$\_$code $=$ codegen.generate$\_\_$code$()$

print$("$Generated object code: $")$

for line in object$\_$code:

print$($line$)$

except Exception as e:

print$($f$"$parsing error: $\{$e$\}")$