First and Follow Function(Final)

productions=[]
tempProd=[]
nterminals=[]
extra=[]
first={}

follow={}

n = int(input("Number of Grammers: "))
for i in range (0,n):
    gr= input("")
    x=gr[3:].split("|")
    for j in x:
        productions.append(gr[:3]+j)
        tempProd.append(gr[:3]+j)

# productions=["S->aSe","S->B","B->bBCf","B->C","C->cCg","C->d","C->#",]
# tempProd=["S->aSe","S->B","B->bBCf","B->C","C->cCg","C->d","C->#",]


# tempProd.sort(key=lambda p: p[3].upper())

#sort lowercase first
print("Sorting")
productions.sort(key=lambda p: p[3].lower())
[print(i) for i in productions]

print("\nNon Terminals:")
for i in productions:
    if i[0] not in nterminals:
        nterminals.extend(i[0])
[print(i) for i in nterminals]


print("\nInitial Dictionaries:")
for i in range(0,len(nterminals)):
        first[nterminals[i]]=[]
[print(f"{i}:{j}") for i,j in first.items()]

#for terminal symbols
for i in range(0,len(nterminals)):
    for j in range(0,len(productions)):
        if nterminals[i]==productions[j][0]:
            if((productions[j][3].isupper()==False) or productions[j][3]=="#"):
                first[nterminals[i]].extend(productions[j][3])

print("\nAfter appending terminals:")
[print(f"{i}:{j}") for i,j in first.items()]


#List out productions starting with a Non-Terminal
print("productions starting with a Non-Terminal")
[extra.append(i) for i in productions if i[3].isupper()]
[print(i) for i in extra]

for z in range(3):
    print("\nAfter appending terminals:")
    [print(f"{i}:{j}") for i,j in first.items()]
    for i in range(0,len(extra)):
        count=0
        for j in extra[i][3:]:
            count+=1
            if j.isupper() and count==len(extra[i][3:]):
                first[extra[i][0]].extend(first[j])
                break

            if j.isupper():
                if '#' in first[j]:
                    first[j].remove('#')
                    first[extra[i][0]].extend(first[j])
                    first[j].extend('#')
                elif '#' not in first[j]:
                    first[extra[i][0]].extend(first[j])
                    break
            elif j.isupper()==False:
                first[extra[i][0]].extend(j)
                break


#To Uniquely Identify
for i in first.keys():
    first[i]=list(set(first[i]))

print("\nFirst FUnction:")
[print(f"First({i})={j}") for i,j in first.items()]


#--------------------------------FOLLOW FUNCTION-----------------------

print("\n\nInitial Follow Dictionary:")
for i in range(0,len(nterminals)):
        follow[nterminals[i]]=[]
[print(f"{i}:{j}") for i,j in follow.items()]




print("Main Follow:")
#CASE-0:Initial case:
follow[tempProd[0][0]].extend('$')

#CASE-1: If follower is a terminal.
for i in range(0,len(tempProd)):     # productions[i]
    temp=0
    flag=0
    for k in tempProd[i][3:]:
        if k.isupper()==False and flag==1:
           follow[temp].extend(k)
           break
        if k.isupper():
            temp=k
            flag=1


#----------------------------------1--------------------------------

#CASE-2: If follower is none. (No Follower)
for i in range(0,len(tempProd)):     # productions[i]
    count=0
    for k in tempProd[i][3:]:
        count+=1
        if k.isupper() and count==len(tempProd[i][3:]):
            follow[k].extend(follow[tempProd[i][0]])

#-----------------------------2------------------------------

#CASE-3: If follower is a Non-Terminal
for z in range(3):
    for i in range(0,len(tempProd)):     # productions[i]
        temp=0
        flag=0
        count=0
        for k in tempProd[i][3:]:
            count+=1
            if k.islower() and flag==2:
                follow[temp].extend(k)
            if k.isupper() and flag==1:
                if '#' in first[k]:
                    first[k].remove('#')
                    follow[temp].extend(first[k])
                    first[k].extend('#')
                    flag=2
                    continue
                elif '#' not in first[k]:
                    follow[temp].extend(first[k])
                    break
        #     if k.isupper() and count==len(tempProd[i][3:]):
        #         follow[temp].extend(first[k])
            if k.isupper():
                temp=k
                flag=1


#---------------------------------------3---------------------
#CASE-2: If follower is none. (No Follower)
for i in range(0,len(tempProd)):     # productions[i]
    count=0
    for k in tempProd[i][3:]:
        count+=1
        if k.isupper() and count==len(tempProd[i][3:]):
            follow[k].extend(follow[tempProd[i][0]])
#-----------------------------2------------------------------

#To Uniquely Identify
for i in follow.keys():
    follow[i]=list(set(follow[i]))

print("\nFollw FUnction:")
[print(f"Follow({i})={j}") for i,j in follow.items()]