twisted.logger.LogLevel : API documentation

Class Variable	debug	Debugging events: Information of use to a developer of the software, not generally of interest to someone running the software unless they are attempting to diagnose a software issue.
Class Variable	info	Informational events: Routine information about the status of an application, such as incoming connections, startup of a subsystem, etc.
Class Variable	warn	Warning events: Events that may require greater attention than informational events but are not a systemic failure condition, such as authorization failures, bad data from a network client, etc. Such events are of potential interest to system administrators, and should ideally be phrased in such a way, or documented, so as to indicate an action that an administrator might take to mitigate the warning.
Class Variable	error	Error conditions: Events indicating a systemic failure, such as programming errors in the form of unhandled exceptions, loss of connectivity to an external system without which no useful work can proceed, such as a database or API endpoint, or resource exhaustion. Similarly to warnings, errors that are related to operational parameters may be actionable to system administrators and should provide references to resources which an administrator might use to resolve them.
Class Variable	critical	Critical failures: Errors indicating systemic failure (ie. service outage), data corruption, imminent data loss, etc. which must be handled immediately. This includes errors unanticipated by the software, such as unhandled exceptions, wherein the cause and consequences are unknown.
Class Method	levelWithName	Get the log level with the given name.
Class Method	_priorityForLevel	No summary

debug =

Debugging events: Information of use to a developer of the software, not generally of interest to someone running the software unless they are attempting to diagnose a software issue.

info =

Informational events: Routine information about the status of an application, such as incoming connections, startup of a subsystem, etc.

warn =

Warning events: Events that may require greater attention than informational events but are not a systemic failure condition, such as authorization failures, bad data from a network client, etc. Such events are of potential interest to system administrators, and should ideally be phrased in such a way, or documented, so as to indicate an action that an administrator might take to mitigate the warning.

error =

Error conditions: Events indicating a systemic failure, such as programming errors in the form of unhandled exceptions, loss of connectivity to an external system without which no useful work can proceed, such as a database or API endpoint, or resource exhaustion. Similarly to warnings, errors that are related to operational parameters may be actionable to system administrators and should provide references to resources which an administrator might use to resolve them.

critical =

Critical failures: Errors indicating systemic failure (ie. service outage), data corruption, imminent data loss, etc. which must be handled immediately. This includes errors unanticipated by the software, such as unhandled exceptions, wherein the cause and consequences are unknown.

@classmethod
def levelWithName(cls, name): (source)

Get the log level with the given name.

Parameters	name	The name of a log level. (type: `str` (native string))
Returns	The `LogLevel` with the specified `name`. (type: `LogLevel`)
Raises	InvalidLogLevelError	if the `name` does not name a valid log level.

@classmethod
def _priorityForLevel(cls, level): (source)

We want log levels to have defined ordering - the order of definition - but they aren't value constants (the only value is the name). This is arguably a bug in Twisted, so this is just a workaround for until this is fixed in some way.

Parameters	level	A log level. (type: `LogLevel`)
Returns	A numeric index indicating priority (lower is higher level). (type: `int`)

twisted.logger.LogLevel(Names) class documentation

`twisted.logger.LogLevel(Names)` class documentation