Module Contents#



Formatter instances are used to convert a LogRecord to text.


create_logger([dirpath, name])

Create a logger instance named bw2calc that can be used to log calculations.



class bw2calc.log_utils.JSONFormatter(fmt=None, datefmt=None, style='%', validate=True, *, defaults=None)[source]#

Bases: logging.Formatter

Inheritance diagram of bw2calc.log_utils.JSONFormatter

Formatter instances are used to convert a LogRecord to text.

Formatters need to know how a LogRecord is constructed. They are responsible for converting a LogRecord to (usually) a string which can be interpreted by either a human or an external system. The base Formatter allows a formatting string to be specified. If none is supplied, the style-dependent default value, “%(message)s”, “{message}”, or “${message}”, is used.

The Formatter can be initialized with a format string which makes use of knowledge of the LogRecord attributes - e.g. the default value mentioned above makes use of the fact that the user’s message and arguments are pre- formatted into a LogRecord’s message attribute. Currently, the useful attributes in a LogRecord are described by:

%(name)s Name of the logger (logging channel) %(levelno)s Numeric logging level for the message (DEBUG, INFO,


%(levelname)s Text logging level for the message (“DEBUG”, “INFO”,


%(pathname)s Full pathname of the source file where the logging

call was issued (if available)

%(filename)s Filename portion of pathname %(module)s Module (name portion of filename) %(lineno)d Source line number where the logging call was issued

(if available)

%(funcName)s Function name %(created)f Time when the LogRecord was created (time.time()

return value)

%(asctime)s Textual time when the LogRecord was created %(msecs)d Millisecond portion of the creation time %(relativeCreated)d Time in milliseconds when the LogRecord was created,

relative to the time the logging module was loaded (typically at application startup time)

%(thread)d Thread ID (if available) %(threadName)s Thread name (if available) %(process)d Process ID (if available) %(message)s The result of record.getMessage(), computed just as

the record is emitted

Initialize the formatter with specified format strings.

Initialize the formatter either with the specified format string, or a default as described above. Allow for specialized date formatting with the optional datefmt argument. If datefmt is omitted, you get an ISO8601-like (or RFC 3339-like) format.

Use a style parameter of ‘%’, ‘{’ or ‘$’ to specify that you want to use one of %-formatting, str.format() ({}) formatting or string.Template formatting in your format string.

Changed in version 3.2: Added the style parameter.


Format the specified record as text.

The record’s attribute dictionary is used as the operand to a string formatting operation which yields the returned string. Before formatting the dictionary, a couple of preparatory steps are carried out. The message attribute of the record is computed using LogRecord.getMessage(). If the formatting string uses the time (as determined by a call to usesTime(), formatTime() is called to format the event time. If there is exception information, it is formatted using formatException() and appended to the message.

json_record(message, extra, record)[source]#
bw2calc.log_utils.create_logger(dirpath=None, name=None, **kwargs)[source]#

Create a logger instance named bw2calc that can be used to log calculations.

dirpath is the directory where the log file is saved. If dirpath is None, no logger is created.

name is the name of the calculation run, used to construct the log filepath.

You can add other types of loggers, just add another handler to the bw2calc named logger before starting your calculations.

Returns the filepath of the created log file.

TODO: Decide on whether we copy safe_filepath to this package or create a common core package.