The complexity of the in operator in Python for a list is typically O(n), where n is the length of the list. It performs a linear search, iterating through each element in the list until a match is found or the end of the list is reached.

The provided code snippet is essentially implementing the same functionality as the in operator. It iterates through each element in the list L and checks if the element e is equal to the target value x. If a match is found, it returns True; otherwise, it returns False. Therefore, the complexity of the find function is also O(n), as it performs a linear search through the list.

Both the in operator and the find function have a similar time complexity, but the in operator is generally preferred for its simplicity and readability.