qi.logging API

Introduction

The module provides logging capabilities integrated with the qi sdk. It’s for most of the API mapped on standard logging facility for python. The module provides a lot of functionality and flexibility.

Warning

The debug log level is not available in python, because there is no debug build in python. Use verbose instead.

There are two ways to use this module:

• Use qi.Logger object with defined category
• Use static methods without defined category

qi.Logger Object Reference

Loggers have the following attributes and methods. Note that Loggers are never instantiated directly, but always through the module-level function qi.logging.Logger(category).

The category is potentially a period-separated hierarchical value, like foo.bar.baz (though it could also be just plain foo, for example). This category will be the default category print by your logger inside your logs.

Class qi.Logger

Logger.fatal(msg[, *args])

Logs a message with level FATAL on the logger. The msg is the message format string, and the args are the arguments which are merged into msg using the string formatting operator.

import qi.logging

logger = qi.logging.Logger("network")
logger.fatal("Protocol problem: ", "connection reset")

would print something like:

[F] 1458553342.543230 3630 network: Protocol problem: connection reset

Logger.error(msg[, *args])

Logs a message with level ERROR on the logger. The arguments are interpreted as for fatal().

Logger.warning(msg[, *args])

Logs a message with level WARNING on the logger. The arguments are interpreted as for fatal().

Logger.info(msg[, *args])

Logs a message with level INFO on the logger. The arguments are interpreted as for fatal().

Logger.verbose(msg[, *args])

Logs a message with level VERBOSE on the logger. The arguments are interpreted as for fatal().

Static Methods Reference

qi.logging.setLevel(lvl)

Sets the threshold to lvl. Logging messages which are less severe than lvl will be ignored. When a handler is created, the level is set to INFO (which causes all messages to be processed except VERBOSE).

import qi.logging

logger = qi.logging.Logger("test.logging")
qi.logging.setLevel(qi.logging.WARNING)

would only print logs more severe or equal than WARNING (ei: FATAL, ERROR, WARNING)

qi.logging.setContext(ctx)

Sets differents context when printing logs. Context ctx is a bit field (integer). All different contexts are listed below. You can add different contexts to get multiple information.

1	Verbosity
2	Short Verbosity
4	System Date
8	Thread ID
16	Category
32	File
64	Function
128	End Of Line
256	Date

Here is some useful values

26	Short Verbosity + Thread ID + Category
30	Short Verbosity + Thread ID + System Date + Category
126	Short Verbosity + Thread ID + System Date + Category + File + Function
254	Short Verbosity + Thread ID + System Date + Category + File + Function + EOL

qi.logging.setFilters(filters)

Sets filters to display only logs that match filters categories rules. Rules are separated by colon. Each category can include a ‘*’ for globbing. Each rules can be:

• +CAT: enable category CAT
• -CAT: disable category CAT
• CAT=level: set category CAT to level

import qi.logging

logger = qi.logging.Logger("test.logging")
qi.logging.setFilters("qi.*=verbose:-qi.foo:+qi.foo.bar")

would print all qi.* logs in INFO and remove all qi.foo logs except qi.foo.bar.

qi.logging.fatal(cat, msg[, *args])

Logs a message with level FATAL and category cat on the logger. The msg is the message format string, and the args are the arguments which are merged into msg using the string formatting operator.

import qi.logging

qi.logging.fatal("network", "Protocol problem: ", "connection reset")

would print something like:

[F] 1458553342.543230 3630 network: Protocol problem: connection reset

qi.logging.error(cat, msg[, *args])

Logs a message with level ERROR on the logger. The arguments are interpreted as for fatal().

qi.logging.warning(cat, msg[, *args])

Logs a message with level WARNING on the logger. The arguments are interpreted as for fatal().

qi.logging.info(cat, msg[, *args])

Logs a message with level INFO on the logger. The arguments are interpreted as for fatal().

qi.logging.verbose(cat, msg[, *args])

Logs a message with level VERBOSE on the logger. The arguments are interpreted as for fatal().