How to avoid multiple flat if conditions in python?

Consider the snippet

def check_conditions(range_of_numbers):

list1 = []
if condition1:
   list1.append("message1")
if condition2:
   list1.append("message2")
if condition3:
   list1.append("message3")
try:
   for i in range_of_numbers:
       int(i)
except ValueError:
    list1.append("message4")
return message

I want to have a list in the with messages only if the conditions were satisfied. I do not use multiple if's since it adds on to the code complexity and every time a new parameter is added I would end up adding a new if condition.