loguru.parser

class Parser

An object to more easily parse generated logs.

The Parser provide a set of handful methods likely to be used while parsing logs for post-processing.

You should not instaniate a Parser by yourself, use from loguru import parser instead.

static cast(_dict, **kwargs)

Convert values of a dict to others defined types.

This is a convenient function used to cast dict values resulting from parsed logs from str to a more appropriate type.

Parameters:

• _dict (dict) – The dict to which values type should be changed.
• **kwargs – Mapping between keys of the input _dict and the function that should be used to convert the associated value.

Returns:

dict – A copy of the input dictionnary with values converted to the appropriate type.

Example

>>> dico = {"some": "text", "num": "42", "date": "2018-09-12 22:23:24"}
>>> parser.cast(dico, num=int, date=lambda t: datetime.strptime(t, "%Y-%m-%d %H:%M:%S")
{'some': 'text', 'num': 42, 'date': datetime.datetime(2018, 9, 12, 22, 23, 24)}

static parse(file, pattern, *, chunk=65536)

Parse raw logs to extract each entry as a dict.

The logging format has to be specified as the regex pattern, it will then be used to parse the file and retrieve each entries based on the named groups present in the regex.

Parameters:

• file (str, pathlib.Path or file-like object) – The path of the log file to be parsed, or alternatively an already opened file object.
• pattern (str or re.Pattern) – The regex to use for logs parsing, it should contain named groups which will be included in the returned dict.
• chunk (int, optional) – The number of bytes read while iterating through the logs, this avoid having to load the whole file in memory.

Yields:

dict – The dict mapping regex named groups to matched values, as returned by re.Match.groupdict().

Examples

>>> reg = r"(?P<lvl>[0-9]+): (?P<msg>.*)"    # If log format is "{level.no} - {message}"
>>> for e in parser.parse("file.log", reg):  # A file line could be "10 - A debug message"
...     print(e)                             # => {'lvl': '10', 'msg': 'A debug message'}