Gil

Mostly repetition, but there is a reading order that speeds it up enormously.

• Read the last line first. That is the exception type and message, and it tells you what went wrong.
• Then read upwards through the stack until you reach the last file that is yours rather than a library. That is where it went wrong.
• Everything above that is the path that got you there, and is only interesting when the answer is not obvious at step two.

So: what, then where, then how. Most people read top to bottom, drown in library frames and give up. Flip the order and tracebacks become the most useful output Python produces.

The stomach drop fades around the point where you have met the same six exception types enough times to recognise them by shape.

You appended the same dictionary forty times. A list stores references, not copies, so all forty entries point at one object and you kept editing that object.

Fix: create the dict inside the loop. First line of the loop body is record = {}, fill it, append it.

If you genuinely need a template each time, dict(template) or template.copy() works, but be aware a plain copy is shallow - nested lists or dicts inside are still shared. copy.deepcopy handles that and you rarely need it.

You now have the vocabulary: mutable objects, references, aliasing. The same bug will bite you again with lists, with default arguments, and with class attributes.

It will. def f(items=[]) is the classic. That empty list is created once when the function is defined, not on each call.

Tag models and set a cost alert if your platform allows it. Finding this on a bill a month later is the expensive way to learn.

Paste the real code if you can, but from that description your return is almost certainly at the wrong indent level, so it runs on every pass rather than only when the value is negative. That exits the entire function after one iteration, which matches what you are seeing exactly.

Two other things while you are in there. Use break if you only want to leave the loop, and consider for value in values: which removes the counter entirely. The fact that you are not stuck in an infinite loop means your i += 1 is fine.

Nobody sees their own indentation. It is the most common thing in this room by a distance.

Also check whether the API pull is deterministic. If you request 'the last 24 hours' at retry time you get a different window than the original attempt, and then even a perfect merge produces different data. Pin the window to the logical execution time, never to now().

Worth adding: when a venv is genuinely active, sys.executable points inside the .venv folder. If it does not, the venv is not active no matter what your prompt says.

python -m pip install rather than pip install. That one habit removes about 80 percent of this whole category of problem forever. It is not a workaround, it is simply the correct way to invoke it.

Mild disagreement on the order. Try python -m venv and pip first, because most packages that used to need a compiler now ship Windows wheels. If it installs, you have saved yourself a whole parallel package manager. If it fails with a wall of red about vcvarsall, then reach for conda.

The first six weeks is when you find all the assumptions. It gets quieter. It never becomes zero.