Python Flashcards
(27 cards)
Data Structure: deque
import
from collections import deque
Data Structure: deque
method(s): append & appendleft
usage with space & time complexity
append(val) & appendleft(val) - adds item
Time: O(1)
Space: O(1)
Data Structure: deque
method(s): pop & popleft
usage with space & time complexity
pop() & popleft() - removes and returns item
Time: O(1)
Space: O(1)
Data Structure: deque
method(s): index
usage with space & time complexity
index(ele, beg, end) - returns first index of value
Time: O(n)
Space: O(1)
Data Structure: deque
method(s): insert
usage with space & time complexity
insert(i, a) - This function inserts the value mentioned in arguments(a) at index(i) specified in arguments.
Time: O(n)
Space: O(1)
Data Structure: deque
method(s): remove
usage with space & time complexity
remove(val) - This function removes the first occurrence of the value mentioned in arguments.
Time: O(n)
Space: O(1)
Data Structure: deque
method(s): count
usage with space & time complexity
count(val) - This function counts the number of occurrences of value mentioned in arguments.
Time: O(n)
Space: O(1)
Data Structure: deque
method(s): extend & extendleft
usage with space & time complexity
extend(iterable):- add multiple values at the right end of the deque.
extendleft(iterable):- add multiple values at the left end of the deque. Order is reversed as a result of left appends.
Time: O(K)
Space: O(1)
Data Structure: deque
method(s): reverse
usage with space & time complexity
reverse():- This function is used to reverse the order of deque elements.
Time: O(n)
Space: O(1)
Data Structure: deque
method(s): rotate
usage with space & time complexity
rotate():- This function rotates the deque by the number specified in arguments. If the number specified is negative, rotation occurs to the left. Else rotation is to right.
Time: O(K)
Space: O(1)
Data Structure: OrderedDict
import
from collections import OrderedDict
Data Structure: OrderedDict
method(s): get item
usage with space & time complexity
dict[key] - returns value
Time: O(1)
Space: O(n)
Data Structure: OrderedDict
method(s): set item
usage with space & time complexity
dict[key] = value
Time: O(1)
Space: O(n)
Data Structure: OrderedDict
method(s): popitem
usage with space & time complexity
popitem() - used to delete an item from the beginning
popitem(last=True) - used to delete an item from the end
Time: O(1)
Space: O(n)
Data Structure: OrderedDict
method(s): move_to_end
usage with space & time complexity
move_to_end(key, last = True) - move an existing key of the dictionary in the end or beginning
Time: O(1)
Space: O(1)
Data Structure: LifoQueue
import
from queue import LifoQueue
Data Structure: LifoQueue
method(s): instantiate
usage
queue = LifoQueue(maxsize=3)
Data Structure: LifoQueue
methods
qsize() - gets the max size of the stack
get() - gets the latest element on the stack
put(val) - adds an element on the stack
full() - displays if the stack is full
empty() - displays if the stack is empty
Data Structure: List
array concat/extend with space & time complexity
”+” method - O(n) space & time where n is all items in both lists
extend() - appends multiple items in O(n) time, where n is the new list items
Data Structure: List
method(s): copy
usage with space & time complexity
array.copy() - move an existing key of the dictionary in the end or beginning
Time: O(n)
Space: O(n)
Data Structure: List
method(s): append
usage with space & time complexity
array.append(val) - adds item to end of array
Time: O(1)
Space: O(1)
Data Structure: List
method(s): pop
usage with space & time complexity
array.pop(i) - removes item from end of array or at specific index
Time: O(1) at end or O(n) intermediate
Space: O(1)
Data Structure: List
method(s): insert
usage with space & time complexity
array.insert(i, val) - inserts an item at the specified position in the array
Time: O(n)
Space: O(1)
Data Structure: List
method(s): remove
usage with space & time complexity
array.remove(val) - removes the first matching item in the array
Time: O(n)
Space: O(1)