Class Counter

prometheus_client/metrics.py:290–367

A Counter tracks counts of events or running totals. Example use cases for Counters: - Number of requests processed - Number of items that were inserted into a queue - Total amount of data that a system has processed Counters can only go up (and be reset when the process restar

class Counter(MetricWrapperBase):
    """A Counter tracks counts of events or running totals.

    Example use cases for Counters:
    - Number of requests processed
    - Number of items that were inserted into a queue
    - Total amount of data that a system has processed

    Counters can only go up (and be reset when the process restarts). If your use case can go down,
    you should use a Gauge instead.

    An example for a Counter:

        from prometheus_client import Counter

        c = Counter('my_failures_total', 'Description of counter')
        c.inc()     # Increment by 1
        c.inc(1.6)  # Increment by given value

    There are utilities to count exceptions raised:

        @c.count_exceptions()
        def f():
            pass

        with c.count_exceptions():
            pass

        # Count only one type of exception
        with c.count_exceptions(ValueError):
            pass
            
    You can also reset the counter to zero in case your logical "process" restarts
    without restarting the actual python process.

       c.reset()

    """
    _type = 'counter'

    def _metric_init(self) -> None:
        self._value = values.ValueClass(self._type, self._name, self._name + '_total', self._labelnames,
                                        self._labelvalues, self._documentation)
        self._created = time.time()

    def inc(self, amount: float = 1, exemplar: Optional[Dict[str, str]] = None) -> None:
        """Increment counter by the given amount."""
        self._raise_if_not_observable()
        if amount < 0:
            raise ValueError('Counters can only be incremented by non-negative amounts.')
        self._value.inc(amount)
        if exemplar:
            _validate_exemplar(exemplar)
            self._value.set_exemplar(Exemplar(exemplar, amount, time.time()))

    def reset(self) -> None:
        """Reset the counter to zero. Use this when a logical process restarts without restarting the actual python process."""
        self._value.set(0)