[Python] Why python prometheus client collectors create metric object every time when collect...

https://github.com/prometheus/client_python/blob/master/prometheus_client/gc_collector.py

import gc
import platform
from typing import Iterable

from .metrics_core import CounterMetricFamily, Metric
from .registry import Collector, CollectorRegistry, REGISTRY


class GCCollector(Collector):
"""Collector for Garbage collection statistics."""

def __init__(self, registry: CollectorRegistry = REGISTRY):
if not hasattr(gc, 'get_stats') or platform.python_implementation() != 'CPython':
return
registry.register(self)

def collect(self) -> Iterable[Metric]:
collected = CounterMetricFamily(
'python_gc_objects_collected',
'Objects collected during gc',
labels=['generation'],
)
uncollectable = CounterMetricFamily(
'python_gc_objects_uncollectable',
'Uncollectable objects found during GC',
labels=['generation'],
)

collections = CounterMetricFamily(
'python_gc_collections',
'Number of times this generation was collected',
labels=['generation'],
)

for gen, stat in enumerate(gc.get_stats()):
generation = str(gen)
collected.add_metric([generation], value=stat['collected'])
uncollectable.add_metric([generation], value=stat['uncollectable'])
collections.add_metric([generation], value=stat['collections'])

return [collected, uncollectable, collections]


Instead of re-using metric object it creates it every time just to log one value. What if I need to pull metric every second? does it mean it will create it every second? it's not an optimal at all. I feel that under certain circumstances it may contribute into memory allocation even more than time app

What I'm missing? Is it by design?

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