<problem>
The four compass points can be abbreviated by single-letter strings as “N”, “E”, “S”, and “W”. Write a function `turn_clockwise (compass_point:str)` that takes one of these four compass points as its parameter, and returns the next compass point in the clockwise direction. If `compass_point` has another value that's distinct from the four compass points listed earlier, return the value None.

## Example Cases:
```
turn_clockwise("N") => "E"
turn_clockwise("W") => "N"
turn_clockwise("S") => "W"
turn_clockwise("E") => "S"
turn_clockwise(42) => None
turn_clockwise("rubbish") => None
```
</problem>
<bug_code>
1. def turn_clockwise(compass_point):
2.    if compass_point = "N":
3.        return "E"
4.    elif compass_point = "E":
5.        return "S"
6.    elif compass_point = "S":
7.        return "W"
8.    elif compass_point = "W":
9.        return "N"
10.    else:
11.        return None
</bug_code>
<bug_desc>
There are syntax errors on lines 2, 4, 6, and 8.
</bug_desc>
<bug_fixes>
Replace `=` with `==` on lines 2, 4, 6, and 8.
</bug_fixes>
<unit_tests>
assert turn_clockwise("N") == "E"
assert turn_clockwise("W") == "N" 
assert turn_clockwise("S") == "W"
assert turn_clockwise("E") == "S"
assert turn_clockwise(42) == None
assert turn_clockwise("rubbish") == None
</unit_tests>
<stu_desc>

</stu_desc>
<dialogue>
User: Hello! I am having trouble with the code can you help me? It's throwing an error.
Assistant: What is the error that you observe?
	<alt>Let's start with a warm-up exercise. How do you assign the value "N" to a variable `compass_point`?
	<alt>Can you describe what your code is trying to do?
User: I have a syntax error on line 2. I'm not sure why.
	<alt>The terminal says "SyntaxError: invalid syntax"
Assistant: Can you describe what you are trying to do on line 2?
	<alt>Ah. Can you show me how you would assign the value "N" to a variable `compass_point`?
	<alt>What operator do you use to assign a value?
	<alt>What operator do you use to check for equality?
	<alt>Can you show me how you would assign the value 1 to a variable `x`?
User: I am trying to check if `compass_point` is equal to "N"
Assistant: What operator do you use to check for equality?
	<alt>Ah. Can you show me how you would assign the value "N" to a variable `compass_point`?
	<alt>What operator do you use to assign a value?
User: I use the `=` operator to check for equality.
	<alt>Oh! I should be using `==` instead of `=` to check equality
Assistant: Ah. Can you show me how you would assign the value "N" to a variable `compass_point`?
	<alt>Can you show me how you would assign the value 1 to a variable `x`?
	<alt>What operator do you use to assign a value?
User: I would use `compass_point = "N"`
	<alt>Oh! I should be using `==` instead of `=` to check equality
Assistant: Are you sure that you can use the same operator `=` for assignment and to check for equality?
User: Oh! I checked the documentation. I should be using `==` instead of `=` to check equality. Let me edit my code.
	<alt>What operator should I use?
<code>
1. def turn_clockwise(compass_point):
2.    if compass_point == "N":
3.        return "E"
4.    elif compass_point == "E":
5.        return "S"
6.    elif compass_point == "S":
7.        return "W"
8.    elif compass_point == "W":
9.        return "N"
10.   else:
11.        return None

</code>
Assistant: Good. Let me know if you have any other questions!
User: Thank you so much for your help!
</dialogue>