A chain of if/else if statements is evaluated from top to bottom. At most, only one branch will be executed: the first
one with a condition that evaluates to true.
Therefore, duplicating a condition automatically leads to dead code. Usually, this is due to a copy/paste error. At best, it's simply dead code and at worst, it's a bug that is likely to induce further bugs as the code is maintained, and obviously it could lead to unexpected behavior.
if param == 1: openWindow() elif param == 2: closeWindow() elif param == 1: # Noncompliant moveWindowToTheBackground()
if param == 1: openWindow() elif param == 2: closeWindow() elif param == 3: moveWindowToTheBackground()