Replace flag loops with any() and all()

"Is any reading too hot?" and "are all orders paid?" are questions, and Python has a built-in for each. Both stop as soon as they know the answer.

Before

readings = [21.5, 22.0, 38.9, 21.8]

too_hot = False
for r in readings:
    if r > 35:
        too_hot = True
        break
print(too_hot)

True

Six lines, a flag and a break, to ask one question.

After

readings = [21.5, 22.0, 38.9, 21.8]

print(any(r > 35 for r in readings))
print(all(18 <= r <= 25 for r in readings))

True
False

They stop early

any() stops at the first true value, all() at the first false one. You can watch it happen:

def too_hot(r):
    print("checking", r)
    return r > 35

print(any(too_hot(r) for r in [21.5, 38.9, 22.0]))

checking 21.5
checking 38.9
True

22.0 is never checked. On a long list, or with a slow check, that's real time saved.

Why it works

The argument without square brackets is a generator expression: it produces one value at a time, only when asked. any() asks for the next value until it gets a true one. With square brackets, any([too_hot(r) for r in readings]), the whole list is built first and every check runs, so the short-circuit is lost.

When not to use it

Watch the empty case: any([]) is False and all([]) is True (nothing broke the rule). If "no orders" should not count as "all paid", check for emptiness first. And if you need which item matched, not just whether one did, use next((r for r in readings if r > 35), None) instead.