How to properly handle if without else in test coverage

The if statement documentation is defining else as optional element:

if_stmt ::=  "if" expression ":" suite
             ( "elif" expression ":" suite )*
             ["else" ":" suite]

So the use of the if statement without else in the following function is perfectly correct:

1 def example_fct(return_foobar):
2    result = "foo"
3
4    if return_foobar:
5       result  += "bar"
6
7    return result 

I fully cover this function by two tests:

import unittest
from example_module import example_fct

class MyTestSuite(unittest.TestCase):

    def test_foo(self):
        self.assertEqual(example_fct(False), "foo")

    def test_foo_bar(self):
        self.assertEqual(example_fct(True), "foobar")

If I run the tests, the coverage is missing a branch (the missing else) and reports it as Missing Lines 4->7. I don't want to add a else: pass and test against a branch that's doing nothing. Also if I put # pragma: no cover in the line with the if statement, the lines 4/5 will not be included in the coverage.

So is there a proper way to deal with this issue, without using an else: pass or # pragma: no cover?

I know that I can do a function call in one line like:

boolVar and call_to_func()

to replace:

if boolVar:
   call_to_func()

but this will not work with an assign statement.