Great that you have figured it out. Please next time enclose your code between lines with triple backticks otherwise it shows up incorrectly as you have probably noticed.
This code is not what you probably want:
if guess in (CC[x]):
print("yes")
For example “fax” is being accepted when only “Halifax” should have been accepted:
>>> "fax" in "Halifax"
True
For strings the operator in checks if the left operand is a substring of the right operand. You should use a different operator to check for equality.