depue is a data structure provided by python, thread-safe, powerful than the list
from collections import deque user_list = ['admin', 'root'] User = user_list.pop () # pop-up element list tail, list does not provide a method of operating head Print (User, user_list) # the root [ 'ADMIN'] """ deque is thread-safe guarantee GIL non-thread-safe list """ # def __init__(self, iterable=(), maxlen=None) user_deque = deque(['admin', 'root', 'jet']) # The append to add an element to the end of the deque, i.e. an element is inserted from the right user_deque.append ( ' MD ' ) # Add an element from the head user_deque.appendleft ( ' Fi ' ) # POP pop up from the rear element pop_item = user_deque.pop () Print (pop_item) # From the head of the pop-up element pop_left_item = user_deque.popleft () # Extents to a deque added to the original deque combined deque Note: not return a new deque user_deque.extend (deque (( ' A1 ' , ' A2 ' ))) # Merge into deque deque original elements to the left of user_deque.extendleft (deque ([123, 456, ])) # Counting the number COUNT = user_deque.count (123 ) Print (COUNT) print (user_deque)