handle format string exceptions separately

gallery_dl/exception.py

@@ -18,6 +18,7 @@ Exception
       |    +-- NotFoundError
       |    +-- HttpError
       +-- NoExtractorError
+      +-- FormatError
       +-- StopExtraction
 """
 
@@ -50,5 +51,9 @@ class NoExtractorError(GalleryDLException):
     """No extractor can handle the given URL"""
 
 
+class FormatError(GalleryDLException):
+    """Error while building output path"""
+
+
 class StopExtraction(GalleryDLException):
     """Extraction should stop"""

gallery_dl/job.py

@@ -54,6 +54,10 @@ class Job():
             log.error("The %s at '%s' does not exist", res, self.url)
         except exception.HttpError as exc:
             log.error("HTTP request failed:\n%s", exc)
+        except exception.FormatError as exc:
+            err, obj = exc.args
+            log.error("Applying %s format string failed:\n%s: %s",
+                      obj, err.__class__.__name__, err)
         except exception.StopExtraction:
             pass
         except OSError as exc:

gallery_dl/util.py

@@ -183,10 +183,14 @@ class PathFormat():
 
     def set_directory(self, keywords):
         """Build directory path and create it if necessary"""
-        segments = [
-            text.clean_path(segment.format_map(keywords).strip())
-            for segment in self.directory_fmt
-        ]
+        try:
+            segments = [
+                text.clean_path(segment.format_map(keywords).strip())
+                for segment in self.directory_fmt
+            ]
+        except Exception as exc:
+            raise exception.FormatError(exc, "directory")
+
         self.directory = os.path.join(
             self.get_base_directory(),
             *segments
@@ -209,7 +213,12 @@ class PathFormat():
 
     def build_path(self, sep=os.path.sep):
         """Use filename-keywords and directory to build a full path"""
-        filename = text.clean_path(self.filename_fmt.format_map(self.keywords))
+        try:
+            filename = text.clean_path(
+                self.filename_fmt.format_map(self.keywords))
+        except Exception as exc:
+            raise exception.FormatError(exc, "filename")
+
         self.path = self.directory + sep + filename
         self.realpath = self.realdirectory + sep + filename