How many times was logging.error() called?

Question

Maybe it's just doesn't exist, as I cannot find it. But using python's logging package, is there a way to query a Logger to find out how many times a particular function was called? For example, how many errors/warnings were reported?

Answer 1

The logging module doesn't appear to support this. In the long run you'd probably be better off creating a new module, and adding this feature via sub-classing the items in the existing logging module to add the features you need, but you could also achieve this behavior pretty easily with a decorator:

class CallCounted:
    """Decorator to determine number of calls for a method"""

    def __init__(self,method):
        self.method=method
        self.counter=0

    def __call__(self,*args,**kwargs):
        self.counter+=1
        return self.method(*args,**kwargs)


import logging
logging.error = CallCounted(logging.error)
logging.error('one')
logging.error('two')
print(logging.error.counter)

Output:

ERROR:root:one
ERROR:root:two
2

Answer 2

You can also add a new Handler to the logger which counts all calls:

class MsgCounterHandler(logging.Handler):
    level2count = None

    def __init__(self, *args, **kwargs):
        super(MsgCounterHandler, self).__init__(*args, **kwargs)
        self.level2count = {}

    def emit(self, record):
        l = record.levelname
        if (l not in self.level2count):
            self.level2count[l] = 0
        self.level2count[l] += 1

You can then use the dict afterwards to output the number of calls.