I have this python code that coverts NFA to DFA using subset construction

Can I please get a line by line explaination on how it works?

I have not coded in python in a long time so I need comments to uderstand it

Here is the code:

def powerset$($s$)$: $"""$Generate powerset of a set.""" result $=[[]]$ for elem in s: result.extend$([$x $+[$elem$]$ for x in result$])$ return result def epsilon$\_$closure$($states$,$ transitions$)$: $"""$Compute epsilon closure of a set of states.""" closure $=$ set$($states$)$ stack $=$ list$($states$)$ while stack: state $=$ stack.pop$()$ epsilon$\_$transitions $=$ transitions.get$(($state$,$ None$),[])$ for next$\_$state in epsilon$\_$transitions: if next$\_$state not in closure: closure.add$($next$\_$state$)$ stack.append$($next$\_$state$)$ return frozenset$($closure$)$ def nfa$\_$to$\_$dfa$($nfa$\_$states, nfa$\_$start, nfa$\_$alphabet, nfa$\_$transitions, nfa$\_$final$)$: $"""$Convert NFA to DFA using subset construction.""" dfa$\_$states $=$ set$()$ dfa$\_$transitions $=\{\}$ alphabet $=$ set$($nfa$\_$alphabet$)$ start$\_$closure $=$ epsilon$\_$closure$(\{$nfa$\_$start$\},$ nfa$\_$transitions$)$ dfa$\_$states.add$($start$\_$closure$)$ stack $=[$start$\_$closure$]$ while stack: current$\_$states $=$ stack.pop$()$ for symbol in alphabet: next$\_$states $=$ set$()$ for state in current$\_$states: transitions $=$ nfa$\_$transitions.get$(($state$,$ symbol$),[])$ next$\_$states.update$($transitions$)$ epsilon$\_$closure$\_$set $=$ epsilon$\_$closure$($next$\_$states, nfa$\_$transitions$)$ if epsilon$\_$closure$\_$set not in dfa$\_$states: dfa$\_$states.add$($epsilon$\_$closure$\_$set$)$ stack.append$($epsilon$\_$closure$\_$set$)$ dfa$\_$transitions$[$current$\_$states, symbol$]=$ epsilon$\_$closure$\_$set dfa$\_$start $=$ start$\_$closure dfa$\_$final $=\{$state for state in dfa$\_$states if any$($s in nfa$\_$final for s in state$)\}$ return dfa$\_$states, dfa$\_$start, alphabet, dfa$\_$final, dfa$\_$transitions def display$\_$dfa$($dfa$\_$states, dfa$\_$start, dfa$\_$alphabet, dfa$\_$final, dfa$\_$transitions$)$: $"""$Display the mathematical representation of the DFA.""" print$("$DFA:$")$ print$("1.$ S: Set of States"$)$ print$("",$ dfa$\_$states$)$ print$("2.$ SO: Start State"$)$ print$("",$ dfa$\_$start$)$ print$("3.$ Alphabet"$)$ print$("",$ dfa$\_$alphabet$)$ print$("4.$ F: Final State$($s$)")$ print$("",$ dfa$\_$final$)$ print$("5.$ T: Transitions"$)$ for transition, next$\_$state in dfa$\_$transitions.items$()$: print$($f$"\{$transition$[0]\}--(\{$transition$[1]\})-->\{$next$\_$state$\}")$ def main$()$: # Input NFA details nfa$\_$states $=$ set$($input$("$Enter NFA states $($comma$-$separated$)$: $").$split$(\text{'},\text{'}))$ nfa$\_$start $=$ input$("$Enter NFA start state: $")$ nfa$\_$alphabet $=$ set$($input$("$Enter NFA alphabet $($comma$-$separated$)$: $").$split$(\text{'},\text{'}))$ nfa$\_$final $=$ set$($input$("$Enter NFA final states $($comma$-$separated$)$: $").$split$(\text{'},\text{'}))$ nfa$\_$transitions $=\{\}$ while True: transition$\_$input $=$ input$("$Enter NFA transition $($state$,$ symbol, next$\_$state$),$ or 'done' to finish: $")$ if transition$\_$input.lower$()==$ 'done': break state, symbol, next$\_$state $=$ transition$\_$input.split$(\text{'},\text{'})$ nfa$\_$transitions$[$state$.$strip$(),$ symbol.strip$()]=$ nfa$\_$transitions.get$(($state$.$strip$(),$ symbol.strip$()),[])+[$next$\_$state.strip$()]$ # Convert NFA to DFA dfa$\_$states, dfa$\_$start, dfa$\_$alphabet, dfa$\_$final, dfa$\_$transitions $=$ nfa$\_$to$\_$dfa$($nfa$\_$states, nfa$\_$start, nfa$\_$alphabet, nfa$\_$transitions, nfa$\_$final$)$ # Display DFA display$\_$dfa$($dfa$\_$states, dfa$\_$start, dfa$\_$alphabet, dfa$\_$final, dfa$\_$transitions$)$ if $\_\_$name$\_\_=="\_\_$main$\_\_"$: main$()$