Implementation of Singly linked list

linked_list.py

class Node:
    def __init__(self, data=None):
        self.data = data
        self.next = None

    def __str__(self):
        return str(self.data)


class SinglyLinkedList:
    def __init__(self):
        self.head = None
        self.tail = None
        self.size = 0

    def clear(self):
        self.tail = None
        self.head = None

    def show(self):
        for word in words.iter():
            print(word)

    def append(self, data):
        # Encapsulate the data in a Node
        node = Node(data)
        self.size += 1

        if self.head:
            self.head.next = node
            self.head = node
        else:
            self.tail = node
            self.head = node

    def iter(self):
        current = self.tail
        while current:
            val = current.data
            current = current.next
            yield val

    def find(self, data):
        current = self.tail
        node = None
        while current:
            if current.data == data:
                node = current
            current = current.next
        return node

    def search(self, data):
        '''Same as search but using iterators'''
        for d in self.iter():
            if data == d:
                return True
        return False

    def delete(self, data):
        current = self.tail
        prev = self.tail
        while current:
            if current.data == data:
                if current == self.tail:
                    self.tail = current.next
                else:
                    prev.next = current.next
                self.size -= 1
                return
            prev = current
            current = current.next


words = SinglyLinkedList()
words.append('eggs')
words.append('ham')
words.append('spam')

words.find('eggs').next.data
words.delete('eggs')
words.search('eggs')
words.show()
words.clear()
words.show()