title: Declaring a strict data type for a variable in Python?
body: <p>In python, is there a command (or a directive) that raises warning when a variable is assigned a value that differs from the previously assigned type?</p>
  
  <pre><code>x = int()   # "x" declared as integer
  y = float() # "y" declared as float
  x = 5       # "x" assigned an integer
  y = 2.75    # "y" assigned a float
  print(x)    # prints "5"
  print(y)    # prints "2.75"
  x = y       # !!! "x" is assigned a float; no warning raised !!!
  print(x)    # prints 2.75
  </code></pre>