Updating the same variabel in an if statement?

I have a continued if statememnt nested in a class definition, with the following lines of code:

if period == 1:  
    var1 = 0  
else:  
    var1 *= OneExpression  
    var1 *= AnotherExpression  
    var1 *= EvenAnotherExpression 

Now I do not really get, what is happening with my var1.
Is it like var1 = first expression and then var1 =first expression times second expression and so on? Or will it just get adjusted according to the code and in the end I only have the solution from EvenAnotherExpression?