$ cat submod.py 
def foo():
    raise OSError

$ cat testcase2.py 
import submod

def func1():
    return

def func2():
    try:
        submod.foo()
    except OSError:
        pass
    func1()

func2()

$ micropython testcase2.py 
Traceback (most recent call last):
  File "testcase2.py", line 14, in <module>
  File "testcase2.py", line 11, in func2
NameError: name 'func1' is not defined