How To

Question 1

Remove all duplicates form a LIst

Answer 1

Turn it into a Set. Sets dont allow duplicates so will remove them automatically BUT it doesnt preserve the original Order as SETS are UNORDERED.

myList = [1,2,2,3,3,3,4]
mySet = set(myList) // This will yield a set with 1,2,3,4

Another way is to use dict.fromKeys() as Dictionaries since python 3.7 are ordered.

my_list = [1, 2, 3, 4, 3, 2, 1]
unique_list = list(dict.fromkeys(my_list))
print(unique_list)

Question 2

Files - open/read/write

Answer 2

with open (‘myfile.txt’) as my_new_file:
contents = my_new_file.read()

with open(‘myfile.txt’, mode=’w+’) as f:
f.write(“hello”)

myfile.read() -> Read entire contents into a String.
myfile.seek(0) -> Rewind file pointer
myfile.readlines() -> Returns list of Strings
myfile.close()

Question 3

How would you implement fifo queue

Answer 3

Add elements to the queue

Using the collections library with deque

from collections import deque

queue = deque([1, 2, 3, 4])

queue.append(5)
queue.append(6)

first_element = queue.popleft() # O(1) operation
second_element = queue.popleft() # O(1) operation

print(first_element) # Output: 1
print(second_element) # Output: 2
print(queue) # Output: deque([3, 4, 5, 6])