Robert Jackson wrote:
> log =
> logging.basicConfig(level=logging.DEBUG,filename="/home/richard/templog",filemode='w')
logging.basicConfig() does not return a logger, it returns None.
> Later in my program I do:
>
> log.info("finished step 4.")
>
> Python spits out this error:
> Traceback (most recent call last):
>
> File "<stdin>", line 1, in <module>
>
> AttributeError: 'NoneType' object has no attribute 'info'
Because log is None and None does not have an 'info' attribute.
>
> I CAN, however, do:
> logging.info("finished step 4.")
Sure, logging is the logging module and it has an info function. This is
normal usage.
> What confuses me about this is that I can do something like this:
>
> # call another function and pass it the logger instance:
>
> foo(logging)
You are not passing a logger, you are passing the logging module itself.
> And, if I define foo() like this:
>
> def foo(log):
>
> # this works fine!
>
> log.info("finished step 4.")
>
> The log.info works fine inside of foo().
Sure, because inside of foo, the name 'log' is bound to the actual
parameter passed in which is the logging module.
> Why is it that I can pass logging as an instance into a function, and
> use whatever instance name I wants inside of foo(),
That is true of every function parameter, you can give them whatever
name you want.
> but I can't assign
> an "alias" for the logging instance inside of main() (by doing instancealias
> = logging.basic())?
Because you are not aliasing logging here. Just assign
log = logging
though I don't see the point, just use logging.info() etc.
Kent
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