feat: add logfmt parser

Fixes: #28

Author: spaceone

src/logfmter/formatter.py

@@ -1,8 +1,9 @@
 import logging
 import numbers
+import shlex
 import traceback
 from types import TracebackType
-from typing import Any, Dict, List, Optional, Tuple, Type, cast
+from typing import Any, Dict, List, Optional, Tuple, Type, Union, cast
 
 ExcInfo = Tuple[Type[BaseException], BaseException, TracebackType]
 
@@ -37,6 +38,30 @@
 )
 
 
+def parse_logfmt(
+    line: str, aliases: Optional[Dict[str, str]] = None, convert_numeric: bool = False
+) -> Dict[str, Union[str, int, float]]:
+    """
+    Parse a logfmt formatted string.
+    """
+    aliases = aliases or {}
+    fields = {}
+    for token in shlex.split(line):
+        key, _, value = token.partition("=")
+        key = aliases.get(key, key)
+        value: Union[str, int, float] = value.replace("\\n", "\n")
+        if convert_numeric and value.isdigit():
+            value = int(value)
+        elif (
+            convert_numeric
+            and value.count(".") == 1
+            and value.replace(".", "").isdigit()
+        ):
+            value = float(value)
+        fields[key] = value
+    return fields
+
+
 class _DefaultFormatter(logging.Formatter):
     def format(self, record):
         exc_info = record.exc_info