Merge pull request #419 from muellerzr/exception

Custom raise message helper

fastcore/_nbdev.py

@@ -190,6 +190,7 @@
          "utc2local": "03_xtras.ipynb",
          "local2utc": "03_xtras.ipynb",
          "trace": "03_xtras.ipynb",
+         "modify_exception": "03_xtras.ipynb",
          "round_multiple": "03_xtras.ipynb",
          "modified_env": "03_xtras.ipynb",
          "ContextManagers": "03_xtras.ipynb",

fastcore/xtras.py

@@ -1,11 +1,18 @@
 # AUTOGENERATED! DO NOT EDIT! File to edit: nbs/03_xtras.ipynb (unless otherwise specified).
 
+
+from __future__ import annotations
+
+
 __all__ = ['dict2obj', 'obj2dict', 'repr_dict', 'is_listy', 'shufflish', 'mapped', 'IterLen', 'ReindexCollection',
            'walk', 'globtastic', 'maybe_open', 'image_size', 'bunzip', 'join_path_file', 'loads', 'loads_multi',
            'untar_dir', 'repo_details', 'run', 'open_file', 'save_pickle', 'load_pickle', 'get_source_link', 'truncstr',
            'spark_chars', 'sparkline', 'autostart', 'EventTimer', 'stringfmt_names', 'PartialFormatter',
-           'partial_format', 'utc2local', 'local2utc', 'trace', 'round_multiple', 'modified_env', 'ContextManagers',
-           'str2bool']
+           'partial_format', 'utc2local', 'local2utc', 'trace', 'modify_exception', 'round_multiple', 'modified_env',
+           'ContextManagers', 'str2bool']
+
+# Cell
+#nbdev_comment from __future__ import annotations
 
 # Cell
 from .imports import *
@@ -467,6 +474,16 @@ def _inner(*args,**kwargs):
     _inner._traced = True
     return _inner
 
+# Cell
+def modify_exception(
+    e:Exception, # An exception
+    msg:str=None, # A custom message
+    replace:bool=False, # Whether to replace e.args with [msg]
+) -> Exception:
+    "Modifies `e` with a custom message attached"
+    e.args = [f'{e.args[0]} {msg}'] if not replace and len(e.args) > 0 else [msg]
+    return e
+
 # Cell
 def round_multiple(x, mult, round_down=False):
     "Round `x` to nearest multiple of `mult`"