Remove All Before

Quiz>

Not all of the elements are important. 

What you need to do here is to remove from the list all of the elements before the given one.

 

example

 

For the illustration we have a list [3, 4, 5] and we need to remove all elements that go before 3 - which is 1 and 2.

 

We have two edge cases here:

(1) if a cutting element cannot be found, then the list shoudn't be changed. 

(2) if the list is empty, then it should remain empty.

 

Input:

List and the border element.

 

Output:

Iterable (tuple, list, iterator ...).

 

Example:

remove_all_before([1, 2, 3, 4, 5], 3) == [3, 4, 5]
remove_all_before([1, 1, 2, 2, 3, 3], 2) == [2, 2, 3, 3]

 

from typing import Iterable


def remove_all_before(items: list, border: int) -> Iterable:
    # your code here
    return items


if __name__ == '__main__':
    print("Example:")
    print(list(remove_all_before([1, 2, 3, 4, 5], 3)))

    # These "asserts" are used for self-checking and not for an auto-testing
    assert list(remove_all_before([1, 2, 3, 4, 5], 3)) == [3, 4, 5]
    assert list(remove_all_before([1, 1, 2, 2, 3, 3], 2)) == [2, 2, 3, 3]
    assert list(remove_all_before([1, 1, 2, 4, 2, 3, 4], 2)) == [2, 4, 2, 3, 4]
    assert list(remove_all_before([1, 1, 5, 6, 7], 2)) == [1, 1, 5, 6, 7]
    assert list(remove_all_before([], 0)) == []
    assert list(remove_all_before([7, 7, 7, 7, 7, 7, 7, 7, 7], 7)) == [7, 7, 7, 7, 7, 7, 7, 7, 7]
    print("Coding complete? Click 'Check' to earn cool rewards!")

 

Solve>

1. items 리스트에 border로 숫자를 받아 해당 위치를 찾아서 시작점으로 두고 슬라이싱 한다.

def remove_all_before(items: list, border: int):
    try:
        return items[items.index(border):]

 

2. ValueError가 발생하면 items 리스트를 반환한다.

def remove_all_before(items: list, border: int):
    except ValueError:
        return items

 

Code>

def remove_all_before(items: list, border: int):
    try:
        return items[items.index(border):]

    except ValueError:
        return items

 

Example>

if __name__ == '__main__':
    print("Example:")
    print(list(remove_all_before([1, 2, 3, 4, 5], 3)))

    # These "asserts" are used for self-checking and not for an auto-testing
    assert list(remove_all_before([1, 2, 3, 4, 5], 3)) == [3, 4, 5]
    assert list(remove_all_before([1, 1, 2, 2, 3, 3], 2)) == [2, 2, 3, 3]
    assert list(remove_all_before([1, 1, 2, 4, 2, 3, 4], 2)) == [2, 4, 2, 3, 4]
    assert list(remove_all_before([1, 1, 5, 6, 7], 2)) == [1, 1, 5, 6, 7]
    assert list(remove_all_before([], 0)) == []
    assert list(remove_all_before([7, 7, 7, 7, 7, 7, 7, 7, 7], 7)) == [
        7, 7, 7, 7, 7, 7, 7, 7, 7]
    print("Coding complete? Click 'Check' to earn cool rewards!")

 

Result>

Example:

[3, 4, 5]

Coding complete? Click 'Check' to earn cool rewards!