Buggy python submission (verdict: Runtime Error):
n=int(input())

for i in range(n):
    cmd=input().split()
    if cmd[0]=="insert":
        dl_list.insert(0,cmd[1])
    elif cmd[0]=="delete":
        try:
            dl_list.remove(cmd[1])
        except:
            print("Error")
    elif cmd[0]=="deleteFirst":
        del dl_list[0]
    elif cmd[0]=="deleteLast":
        del dl_list[-1]

print(*dl_list)

Fixed submission:
from collections import deque
n=int(input())
dq=deque()

for i in range(n):
    cmd=input().split()
    if cmd[0]=="insert":
        dq.appendleft(cmd[1])
    elif cmd[0]=="deleteFirst":
        dq.popleft()
    elif cmd[0]=="deleteLast":
        dq.pop()
    elif cmd[0]=="delete":
        try:
            dq.remove(cmd[1])
        except:
            pass
print(*dq)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())

dl_list=[]

for i in range(n):
    cmd=input().split()
    if cmd[0]=="insert":
        dl_list.insert(0,cmd[1])
    elif cmd[0]=="delete":
        try:
            dl_list.remove(cmd[1])
        except:
            pass
    elif cmd[0]=="deleteFirst":
        del dl_list[0]
    elif cmd[0]=="deleteLast":
        del dl_list[-1]

print(*dl_list)

Fixed submission:
from collections import deque
n=int(input())
dq=deque()

for i in range(n):
    cmd=input().split()
    if cmd[0]=="insert":
        dq.appendleft(cmd[1])
    elif cmd[0]=="deleteFirst":
        dq.popleft()
    elif cmd[0]=="deleteLast":
        dq.pop()
    elif cmd[0]=="delete":
        try:
            dq.remove(cmd[1])
        except:
            pass
print(*dq)

Buggy python submission (verdict: Runtime Error):
n=int(input())

dl_list=[]

for i in range(n):
    cmd=input().split()
    if cmd[0]=="insert":
        dl_list.insert(0,cmd[1])
    elif cmd[0]=="delete":
        try:
            dl_list.remove(cmd[1])
        except:
            pass
    elif cmd[0]=="deleteFirst":
        del dl_list[0]
    elif cmd[0]=="deleteLast":
        del dl_list[-1]

print(" ".join(dl_list)

Fixed submission:
from collections import deque
n=int(input())
dq=deque()

for i in range(n):
    cmd=input().split()
    if cmd[0]=="insert":
        dq.appendleft(cmd[1])
    elif cmd[0]=="deleteFirst":
        dq.popleft()
    elif cmd[0]=="deleteLast":
        dq.pop()
    elif cmd[0]=="delete":
        try:
            dq.remove(cmd[1])
        except:
            pass
print(*dq)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())

dl_list=[]

for i in range(n):
    cmd=input().split()
    if cmd[0]=="insert":
        dl_list.insert(0,cmd[1])
    elif cmd[0]=="delete":
        try:
            dl_list.remove(cmd[1])
        except:
            pass
    elif cmd[0]=="deleteFirst":
        del dl_list[0]
    elif cmd[0]=="deleteLast":
        del dl_list[-1]

print(" ".join(dl_list))

Fixed submission:
from collections import deque
n=int(input())
dq=deque()

for i in range(n):
    cmd=input().split()
    if cmd[0]=="insert":
        dq.appendleft(cmd[1])
    elif cmd[0]=="deleteFirst":
        dq.popleft()
    elif cmd[0]=="deleteLast":
        dq.pop()
    elif cmd[0]=="delete":
        try:
            dq.remove(cmd[1])
        except:
            pass
print(*dq)