DOC: add docstrings

src/caoscrawler/transformer_functions.py

@@ -28,6 +28,9 @@ from typing import Any
 
 
 def ifelse(in_value: Any, in_parameters: dict):
+    """returns the first argument if it does NOT match the reg exp of 'match' stored in the second
+    argument, other wise the value of 'then' stored in the second argument is returned.
+    """
     if "match" not in in_parameters or "then" not in in_parameters:
         raise RuntimeError("Mandatory parameters missing.")
     if re.match(in_parameters["match"], in_value) is not None:
@@ -36,6 +39,9 @@ def ifelse(in_value: Any, in_parameters: dict):
 
 
 def split(in_value: Any, in_parameters: dict):
+    """calls the string 'split' function on the first argument and uses the value of the key
+    'marker' stored in the second argument
+    """
     if "marker" not in in_parameters:
         raise RuntimeError("Mandatory parameter missing.")
     if not isinstance(in_value, str):