Method peek

data_structures/stacks/stack.py:76–93

Peek at the top-most element of the stack. >>> S = Stack() >>> S.push(-5) >>> S.push(10) >>> S.peek() 10 >>> Stack().peek() Traceback (most recent call last): ... data_structures.stacks.stack.StackUnderflowError

(self)

        return self.stack.pop()

    def peek(self) -> T:
        """
        Peek at the top-most element of the stack.

        >>> S = Stack()
        >>> S.push(-5)
        >>> S.push(10)
        >>> S.peek()
        10

        >>> Stack().peek()
        Traceback (most recent call last):
            ...
        data_structures.stacks.stack.StackUnderflowError
        """
        if not self.stack:
            raise StackUnderflowError
        return self.stack[-1]

    def is_empty(self) -> bool:
        """