How can I insert a 'with' statement under a condition?

Question

I have a piece of code structured this way:

try:
    from tqdm import tqdm
    use_tqdm = True
except ImportError:
    use_tqdm = False


if use_tqdm:
    with tqdm(total=5) as pbar:
        # --- many nested for loops ---
        pbar.update(1)
else:
    # --- identical nested for loops, without pbar.update(1) ---

How can I avoid repeating said long block of code?

I cannot put the condition only on the single pbar line inside because what tqdm does is create a progress bar, so it needs to be instantiated only once.

I think I'm looking for a way to tell Python "hey, consider the with statement only if use_tqdm = True, otherwise pretend it never existed", but any other suggestions are very welcome.

Thanks!

(tqdm package: https://github.com/tqdm/tqdm )

Answer 1

try:
    from tqdm import tqdm
except ImportError:
    class tqdm:
        def __int__(self, *args, **kwargs):
            pass

        def __enter__(self):
            class Dummy:
                def update(self, *args, **kwargs):
                    pass

            return Dummy()

        def __exit__(self, *args):
            pass

with tqdm(total = 5) as pbar:
   --- many nested for loops ---
            pbar.update(1)

If the import fails, you just get a dummy context and an object whose update method is a no-op. No separate code is needed.