title: Type int in python: how to check type
body: <p>I use the code:</p>
  
  <p>def foo(x):
      print(type(x))
      if x is not int:
          raise(TypeError)
      #do smth</p>
  
  <p>foo(100)</p>
  
  <p>The log is , but TypeError is raised. Why?</p>