Lazily evaluate log message parameters

[petedmarsh]

Logging like this:

logger.debug("Hello, %s" % name)

causes the message string to always be interpolated even if the message is not going to be logged.

Logging like this:

logger.debug("Hello, %s", name)

will mean the string is only ever interpolated if it will be logged.

In practice here this will make little difference if the log level is INFO or above.

See:

https://docs.python.org/3/howto/logging.html#optimization https://stackoverflow.com/questions/4148790/lazy-logger-message-string-evaluation

[petedmarsh]

I realized I missed a bunch of cases using .format, have fixed those now.