From 45f885df5fb3604def376ea5863d218dbc5589fb Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Tue, 30 May 2023 12:52:00 +0900
Subject: [PATCH 01/12] optional check of I3Filters in dataconverter

---
 src/graphnet/data/dataconverter.py | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index dc0deabd0..3d9304f9f 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -107,6 +107,7 @@ def __init__(
         workers: int = 1,
         index_column: str = "event_no",
         icetray_verbose: int = 0,
+        I3filters: List[str] = [],
     ):
         """Construct DataConverter.
 
@@ -166,6 +167,7 @@ def __init__(
         self._sequential_batch_pattern = sequential_batch_pattern
         self._input_file_batch_pattern = input_file_batch_pattern
         self._workers = workers
+        self._I3filters = I3filters
 
         # Create I3Extractors
         self._extractors = I3ExtractorCollection(*extractors)
@@ -435,6 +437,8 @@ def _extract_data(self, fileset: FileSet) -> List[OrderedDict]:
                     continue
             if self._skip_frame(frame):
                 continue
+            if self._filter_mask(frame, self._I3filters):
+                continue
 
             # Try to extract data from I3Frame
             results = self._extractors(frame)
@@ -566,3 +570,17 @@ def _skip_frame(self, frame: "icetray.I3Frame") -> bool:
         if frame["I3EventHeader"].sub_event_stream == "NullSplit":
             return True
         return False
+
+    def _filter_mask(
+        self, frame: "icetray.I3Frame", I3filters: List[str]
+    ) -> bool:
+        """Check if specified condition(s) are met.
+
+        Args:
+            frame: I3Frame to check.
+            I3filters: List of I3Filters to check for pass.
+        """
+        for filter in I3filters:
+            if frame["FilterMask"][filter].condition_passed is False:
+                return True
+        return False

From faf38bd05dfe3edc94b6db9ecb6c99e2b5a13af1 Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Mon, 25 Sep 2023 09:19:01 +0900
Subject: [PATCH 02/12] checks existence of filters

---
 src/graphnet/data/dataconverter.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 3d9304f9f..616030ae1 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -580,7 +580,17 @@ def _filter_mask(
             frame: I3Frame to check.
             I3filters: List of I3Filters to check for pass.
         """
+        if "FilterMask" not in frame:
+            self.warning_once(
+                "FilterMask not found in frame. Skipping filter checks."
+            )
+            return False
         for filter in I3filters:
+            if filter not in frame["FilterMask"]:
+                self.warning_once(
+                    f"Filter {filter} not found in frame. Skipping."
+                )
+                continue
             if frame["FilterMask"][filter].condition_passed is False:
                 return True
         return False

From 4e3e391057148b4022221b151db8fbee532f3bee Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Mon, 25 Sep 2023 09:38:45 +0900
Subject: [PATCH 03/12] refactoring

---
 src/graphnet/data/dataconverter.py | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 616030ae1..54cbbf418 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -580,17 +580,19 @@ def _filter_mask(
             frame: I3Frame to check.
             I3filters: List of I3Filters to check for pass.
         """
-        if "FilterMask" not in frame:
+        if "FilterMask" in frame:
+            for filter in I3filters:
+                if filter in frame["FilterMask"]:
+                    if frame["FilterMask"][filter].condition_passed is False:
+                        return True
+                else:
+                    self.warning_once(
+                        f"Filter {filter} not found in frame. Skipping filter check."
+                    )
+                    continue
+        else:
             self.warning_once(
                 "FilterMask not found in frame. Skipping filter checks."
             )
             return False
-        for filter in I3filters:
-            if filter not in frame["FilterMask"]:
-                self.warning_once(
-                    f"Filter {filter} not found in frame. Skipping."
-                )
-                continue
-            if frame["FilterMask"][filter].condition_passed is False:
-                return True
         return False

From 5d57ff623e32a53d3118b1d4bd88c4db9b49b6b1 Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Mon, 25 Sep 2023 12:44:00 +0900
Subject: [PATCH 04/12] revert

---
 src/graphnet/data/dataconverter.py | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 54cbbf418..616030ae1 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -580,19 +580,17 @@ def _filter_mask(
             frame: I3Frame to check.
             I3filters: List of I3Filters to check for pass.
         """
-        if "FilterMask" in frame:
-            for filter in I3filters:
-                if filter in frame["FilterMask"]:
-                    if frame["FilterMask"][filter].condition_passed is False:
-                        return True
-                else:
-                    self.warning_once(
-                        f"Filter {filter} not found in frame. Skipping filter check."
-                    )
-                    continue
-        else:
+        if "FilterMask" not in frame:
             self.warning_once(
                 "FilterMask not found in frame. Skipping filter checks."
             )
             return False
+        for filter in I3filters:
+            if filter not in frame["FilterMask"]:
+                self.warning_once(
+                    f"Filter {filter} not found in frame. Skipping."
+                )
+                continue
+            if frame["FilterMask"][filter].condition_passed is False:
+                return True
         return False

From 3f3451fb9c6b15a09b95bd190dbc9b62b4ada6b3 Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Tue, 26 Sep 2023 10:37:22 +0900
Subject: [PATCH 05/12] refactoring

---
 src/graphnet/data/dataconverter.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 616030ae1..92d7ae59b 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -437,7 +437,7 @@ def _extract_data(self, fileset: FileSet) -> List[OrderedDict]:
                     continue
             if self._skip_frame(frame):
                 continue
-            if self._filter_mask(frame, self._I3filters):
+            if self._filter_mask(frame):
                 continue
 
             # Try to extract data from I3Frame
@@ -571,11 +571,11 @@ def _skip_frame(self, frame: "icetray.I3Frame") -> bool:
             return True
         return False
 
-    def _filter_mask(
-        self, frame: "icetray.I3Frame", I3filters: List[str]
-    ) -> bool:
+    def _filter_mask(self, frame: "icetray.I3Frame") -> bool:
         """Check if specified condition(s) are met.
 
+        A 'True' return will skip the frame.
+
         Args:
             frame: I3Frame to check.
             I3filters: List of I3Filters to check for pass.
@@ -585,7 +585,7 @@ def _filter_mask(
                 "FilterMask not found in frame. Skipping filter checks."
             )
             return False
-        for filter in I3filters:
+        for filter in self._I3filters:
             if filter not in frame["FilterMask"]:
                 self.warning_once(
                     f"Filter {filter} not found in frame. Skipping."

From 96264d7187fe77b067936dced05d6d818cdcfbc1 Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Tue, 26 Sep 2023 15:53:22 +0900
Subject: [PATCH 06/12] create filter class

---
 src/graphnet/data/dataconverter.py |  52 +++++-------
 src/graphnet/data/filters.py       | 124 +++++++++++++++++++++++++++++
 2 files changed, 142 insertions(+), 34 deletions(-)
 create mode 100644 src/graphnet/data/filters.py

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 92d7ae59b..51a69d36a 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -21,6 +21,7 @@
     TypeVar,
     Union,
     cast,
+    Sequence,
 )
 
 import numpy as np
@@ -39,6 +40,7 @@
 from graphnet.utilities.filesys import find_i3_files
 from graphnet.utilities.imports import has_icecube_package
 from graphnet.utilities.logging import Logger
+from graphnet.data.filters import I3Filter, NullSplitI3Filter
 
 if has_icecube_package():
     from icecube import icetray, dataio  # pyright: reportMissingImports=false
@@ -107,7 +109,7 @@ def __init__(
         workers: int = 1,
         index_column: str = "event_no",
         icetray_verbose: int = 0,
-        I3filters: List[str] = [],
+        i3_Filters: Union[I3Filter, List[Callable]] = [NullSplitI3Filter],
     ):
         """Construct DataConverter.
 
@@ -167,7 +169,13 @@ def __init__(
         self._sequential_batch_pattern = sequential_batch_pattern
         self._input_file_batch_pattern = input_file_batch_pattern
         self._workers = workers
-        self._I3filters = I3filters
+        if isinstance(i3_Filters, I3Filter):
+            I3_Filters = [i3_Filters]
+        self._I3filters = I3_Filters
+        for filter in self._I3filters:
+            assert isinstance(
+                filter, I3Filter
+            ), f"{type(filter)} is not a subclass of I3Filter"
 
         # Create I3Extractors
         self._extractors = I3ExtractorCollection(*extractors)
@@ -435,10 +443,9 @@ def _extract_data(self, fileset: FileSet) -> List[OrderedDict]:
             except Exception as e:
                 if "I3" in str(e):
                     continue
+            # check if frame should be skipped
             if self._skip_frame(frame):
                 continue
-            if self._filter_mask(frame):
-                continue
 
             # Try to extract data from I3Frame
             results = self._extractors(frame)
@@ -559,38 +566,15 @@ def _get_output_file(self, input_file: str) -> str:
         return output_file
 
     def _skip_frame(self, frame: "icetray.I3Frame") -> bool:
-        """Check if frame should be skipped.
-
-        Args:
-            frame: I3Frame to check.
+        """Check the user defined filters.
 
         Returns:
-            True if frame is a null split frame, else False.
+            bool: True if frame should be skipped, False otherwise.
         """
-        if frame["I3EventHeader"].sub_event_stream == "NullSplit":
-            return True
-        return False
-
-    def _filter_mask(self, frame: "icetray.I3Frame") -> bool:
-        """Check if specified condition(s) are met.
+        if self._I3filters is None:
+            return False  # No filters defined, so we keep the frame
 
-        A 'True' return will skip the frame.
-
-        Args:
-            frame: I3Frame to check.
-            I3filters: List of I3Filters to check for pass.
-        """
-        if "FilterMask" not in frame:
-            self.warning_once(
-                "FilterMask not found in frame. Skipping filter checks."
-            )
-            return False
         for filter in self._I3filters:
-            if filter not in frame["FilterMask"]:
-                self.warning_once(
-                    f"Filter {filter} not found in frame. Skipping."
-                )
-                continue
-            if frame["FilterMask"][filter].condition_passed is False:
-                return True
-        return False
+            if not filter(frame):
+                return True  # A filter keep_frame call has returned false, so we skip the frame
+        return False  # All filter keep_frame calls have returned true, so we keep the frame
diff --git a/src/graphnet/data/filters.py b/src/graphnet/data/filters.py
new file mode 100644
index 000000000..2697e0a53
--- /dev/null
+++ b/src/graphnet/data/filters.py
@@ -0,0 +1,124 @@
+"""Filter classes for filtering I3-frames when converting I3-files."""
+from abc import abstractmethod
+from graphnet.utilities.logging import Logger
+from typing import List
+from icecube import icetray
+
+
+class I3Filter(Logger):
+    """A generic filter for I3-frames."""
+
+    @abstractmethod
+    def _pass_frame(self, frame: icetray.I3Frame) -> bool:
+        """Return True if the frame passes the filter, False otherwise.
+
+        Args:
+            frame: I3-frame
+                The I3-frame to check.
+
+        Returns:
+            bool: True if the frame passes the filter, False otherwise.
+        """
+        raise NotImplementedError
+
+    def __call__(self, frame: icetray.I3Frame) -> bool:
+        """Return True if the frame passes the filter, False otherwise.
+
+        Args:
+            frame: I3-frame
+                The I3-frame to check.
+
+        Returns:
+            bool: True if the frame passes the filter, False otherwise.
+        """
+        pass_flag = self._pass_frame(frame)
+        try:
+            assert isinstance(pass_flag, bool)
+        except AssertionError:
+            raise TypeError(
+                f"Expected _pass_frame to return a bool, got {type(pass_flag)}."
+            )
+        return pass_flag
+
+
+class NullSplitI3Filter(I3Filter):
+    """A filter that skips all null-split frames."""
+
+    def _keep_frame(self, frame: icetray.I3Frame) -> bool:
+        """Check that frame is not a null-split frame.
+
+        returns False if the frame is a null-split frame, True otherwise.
+
+        Args:
+            frame: I3-frame
+                The I3-frame to check.
+        """
+        if frame.Has("I3EventHeader"):
+            if frame["I3EventHeader"].sub_event_stream == "NullSplit":
+                return False
+        return True
+
+
+class I3FilterMask(I3Filter):
+    """checks list of filters from the FilterMask in I3 frames."""
+
+    def __init__(self, filter_names: List[str], filter_any: bool = True):
+        """Initialize I3FilterMask.
+
+        Args:
+        filter_names: List[str]
+            A list of filter names to check for.
+        filter_any: bool
+            standard: True
+            If True, the frame is kept if any of the filter names are present.
+            If False, the frame is kept if all of the filter names are present.
+        """
+        self._filter_names = filter_names
+        self._filter_any = filter_any
+
+    def _keep_frame(self, frame: icetray.I3Frame) -> bool:
+        """Check if current frame should be kept.
+
+        Args:
+            frame: I3-frame
+                The I3-frame to check.
+        """
+        if "FilterMask" in frame:
+            if (
+                self._filter_any is True
+            ):  # Require any of the filters to pass to keep the frame
+                bool_list = []
+                for filter_name in self._filter_names:
+                    if filter_name not in frame["FilterMask"]:
+                        self.warning_once(
+                            f"FilterMask {filter_name} not found in frame.skipping filter."
+                        )
+                        continue
+                    elif frame["FilterMask"][filter].condition_passed is True:
+                        bool_list.append(True)
+                    else:
+                        bool_list.append(False)
+                if len(bool_list) == 0:
+                    self.warning_once(
+                        "None of the FilterMask filters found in frame, FilterMask filters will not be applied."
+                    )
+                return any(bool_list) or len(bool_list) == 0
+            else:  # Require all filters to pass in order to keep the frame.
+                for filter_name in self._filter_names:
+                    if filter_name not in frame["FilterMask"]:
+                        self.warning_once(
+                            f"FilterMask {filter_name} not found in frame, skipping filter."
+                        )
+                        continue
+                    elif frame["FilterMask"][filter].condition_passed is True:
+                        continue  # current filter is passed, continue to next filter
+                    else:
+                        return (
+                            False  # current filter failed so frame is skipped.
+                        )
+                return True
+        else:
+            self.warning_once(
+                "FilterMask not found in frame, FilterMask filters will not be applied."
+            )
+            return True

From 53d4a09abb3d48108316ebf20f88c4d282c2d0af Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Tue, 26 Sep 2023 16:02:12 +0900
Subject: [PATCH 07/12] code_climate_fixes

---
 src/graphnet/data/dataconverter.py | 4 ++--
 src/graphnet/data/filters.py       | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 51a69d36a..1e8b64271 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -576,5 +576,5 @@ def _skip_frame(self, frame: "icetray.I3Frame") -> bool:
 
         for filter in self._I3filters:
             if not filter(frame):
-                return True  # A filter keep_frame call has returned false, so we skip the frame
-        return False  # All filter keep_frame calls have returned true, so we keep the frame
+                return True  # keep_frame call false, skip the frame.
+        return False  # All filter keep_frame calls true, keep the frame.
diff --git a/src/graphnet/data/filters.py b/src/graphnet/data/filters.py
index 2697e0a53..f862ea197 100644
--- a/src/graphnet/data/filters.py
+++ b/src/graphnet/data/filters.py
@@ -36,7 +36,7 @@ def __call__(self, frame: icetray.I3Frame) -> bool:
             assert isinstance(pass_flag, bool)
         except AssertionError:
             raise TypeError(
-                f"Expected _pass_frame to return a bool, got {type(pass_flag)}."
+                f"Expected _pass_frame to return bool, got {type(pass_flag)}."
             )
         return pass_flag
 
@@ -91,7 +91,7 @@ def _keep_frame(self, frame: icetray.I3Frame) -> bool:
                 for filter_name in self._filter_names:
                     if filter_name not in frame["FilterMask"]:
                         self.warning_once(
-                            f"FilterMask {filter_name} not found in frame.skipping filter."
+                            f"FilterMask {filter_name} not found in frame. skipping filter."
                         )
                         continue
                     elif frame["FilterMask"][filter].condition_passed is True:
@@ -111,7 +111,7 @@ def _keep_frame(self, frame: icetray.I3Frame) -> bool:
                         )
                         continue
                     elif frame["FilterMask"][filter].condition_passed is True:
-                        continue  # current filter is passed, continue to next filter
+                        continue  # current filter passed, continue to next filter
                     else:
                         return (
                             False  # current filter failed so frame is skipped.

From 5c4260f8fd3569b8d96506084afc4975a0d759da Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Wed, 27 Sep 2023 09:56:05 +0900
Subject: [PATCH 08/12] add to init

---
 src/graphnet/data/__init__.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/graphnet/data/__init__.py b/src/graphnet/data/__init__.py
index 1eca4f6cd..fbb1ee095 100644
--- a/src/graphnet/data/__init__.py
+++ b/src/graphnet/data/__init__.py
@@ -3,3 +3,4 @@
 `graphnet.data` enables converting domain-specific data to industry-standard,
 intermediate file formats  and reading this data.
 """
+from .filters import I3Filter, I3FilterMask

From 83cce2a1de1ecd4312ade1d6a24a8e265728818b Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Wed, 27 Sep 2023 10:11:59 +0900
Subject: [PATCH 09/12] optional icetray dependency

---
 src/graphnet/data/filters.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/graphnet/data/filters.py b/src/graphnet/data/filters.py
index f862ea197..21a31e429 100644
--- a/src/graphnet/data/filters.py
+++ b/src/graphnet/data/filters.py
@@ -2,14 +2,18 @@
 from abc import abstractmethod
 from graphnet.utilities.logging import Logger
 from typing import List
-from icecube import icetray
+
+from graphnet.utilities.imports import has_icecube_package
+
+if has_icecube_package():
+    from icecube import icetray
 
 
 class I3Filter(Logger):
     """A generic filter for I3-frames."""
 
     @abstractmethod
-    def _pass_frame(self, frame: icetray.I3Frame) -> bool:
+    def _pass_frame(self, frame: "icetray.I3Frame") -> bool:
         """Return True if the frame passes the filter, False otherwise.
 
         Args:
@@ -21,7 +25,7 @@ def _pass_frame(self, frame: icetray.I3Frame) -> bool:
         """
         raise NotImplementedError
 
-    def __call__(self, frame: icetray.I3Frame) -> bool:
+    def __call__(self, frame: "icetray.I3Frame") -> bool:
         """Return True if the frame passes the filter, False otherwise.
 
         Args:
@@ -44,7 +48,7 @@ def __call__(self, frame: icetray.I3Frame) -> bool:
 class NullSplitI3Filter(I3Filter):
     """A filter that skips all null-split frames."""
 
-    def _keep_frame(self, frame: icetray.I3Frame) -> bool:
+    def _keep_frame(self, frame: "icetray.I3Frame") -> bool:
         """Check that frame is not a null-split frame.
 
         returns False if the frame is a null-split frame, True otherwise.
@@ -76,7 +80,7 @@ def __init__(self, filter_names: List[str], filter_any: bool = True):
         self._filter_names = filter_names
         self._filter_any = filter_any
 
-    def _keep_frame(self, frame: icetray.I3Frame) -> bool:
+    def _keep_frame(self, frame: "icetray.I3Frame") -> bool:
         """Check if current frame should be kept.
 
         Args:

From b091cbc84978c965d811a3f55c682ebd805e4d73 Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Thu, 28 Sep 2023 09:58:31 +0900
Subject: [PATCH 10/12] typo-fix

---
 src/graphnet/data/dataconverter.py | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 1e8b64271..eb42dc7a1 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -109,7 +109,7 @@ def __init__(
         workers: int = 1,
         index_column: str = "event_no",
         icetray_verbose: int = 0,
-        i3_Filters: Union[I3Filter, List[Callable]] = [NullSplitI3Filter],
+        I3_Filters: Union[I3Filter, List[Callable]] = [NullSplitI3Filter],
     ):
         """Construct DataConverter.
 
@@ -169,10 +169,10 @@ def __init__(
         self._sequential_batch_pattern = sequential_batch_pattern
         self._input_file_batch_pattern = input_file_batch_pattern
         self._workers = workers
-        if isinstance(i3_Filters, I3Filter):
-            I3_Filters = [i3_Filters]
-        self._I3filters = I3_Filters
-        for filter in self._I3filters:
+        if isinstance(I3_Filters, I3Filter):
+            I3_Filters = [I3_Filters]
+        self._I3Filters = I3_Filters
+        for filter in self._I3Filters:
             assert isinstance(
                 filter, I3Filter
             ), f"{type(filter)} is not a subclass of I3Filter"
@@ -571,10 +571,10 @@ def _skip_frame(self, frame: "icetray.I3Frame") -> bool:
         Returns:
             bool: True if frame should be skipped, False otherwise.
         """
-        if self._I3filters is None:
+        if self._I3Filters is None:
             return False  # No filters defined, so we keep the frame
 
-        for filter in self._I3filters:
+        for filter in self._I3Filters:
             if not filter(frame):
                 return True  # keep_frame call false, skip the frame.
         return False  # All filter keep_frame calls true, keep the frame.

From 12aec80e01acb2dd88362f8391b85de653d7b98d Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Thu, 28 Sep 2023 11:22:12 +0900
Subject: [PATCH 11/12] refactoring/bugfixing

---
 src/graphnet/data/dataconverter.py | 10 +++++-----
 src/graphnet/data/filters.py       |  8 ++++----
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index eb42dc7a1..0f12e7ab5 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -21,7 +21,6 @@
     TypeVar,
     Union,
     cast,
-    Sequence,
 )
 
 import numpy as np
@@ -109,7 +108,7 @@ def __init__(
         workers: int = 1,
         index_column: str = "event_no",
         icetray_verbose: int = 0,
-        I3_Filters: Union[I3Filter, List[Callable]] = [NullSplitI3Filter],
+        I3_Filters: List[I3Filter] = [],
     ):
         """Construct DataConverter.
 
@@ -169,9 +168,10 @@ def __init__(
         self._sequential_batch_pattern = sequential_batch_pattern
         self._input_file_batch_pattern = input_file_batch_pattern
         self._workers = workers
-        if isinstance(I3_Filters, I3Filter):
-            I3_Filters = [I3_Filters]
-        self._I3Filters = I3_Filters
+
+        # I3Filters (NullSplitI3Filter is always included)
+        self._I3Filters = [NullSplitI3Filter()] + I3_Filters
+
         for filter in self._I3Filters:
             assert isinstance(
                 filter, I3Filter
diff --git a/src/graphnet/data/filters.py b/src/graphnet/data/filters.py
index 21a31e429..ca83f4217 100644
--- a/src/graphnet/data/filters.py
+++ b/src/graphnet/data/filters.py
@@ -13,15 +13,15 @@ class I3Filter(Logger):
     """A generic filter for I3-frames."""
 
     @abstractmethod
-    def _pass_frame(self, frame: "icetray.I3Frame") -> bool:
-        """Return True if the frame passes the filter, False otherwise.
+    def _keep_frame(self, frame: "icetray.I3Frame") -> bool:
+        """Return True if the frame is kept, False otherwise.
 
         Args:
             frame: I3-frame
                 The I3-frame to check.
 
         Returns:
-            bool: True if the frame passes the filter, False otherwise.
+            bool: True if the frame is kept, False otherwise.
         """
         raise NotImplementedError
 
@@ -35,7 +35,7 @@ def __call__(self, frame: "icetray.I3Frame") -> bool:
         Returns:
             bool: True if the frame passes the filter, False otherwise.
         """
-        pass_flag = self._pass_frame(frame)
+        pass_flag = self._keep_frame(frame)
         try:
             assert isinstance(pass_flag, bool)
         except AssertionError:

From 8c21d2e57738d12c75d19eb2c159b2d43ab429cd Mon Sep 17 00:00:00 2001
From: Aske-Rosted <askerosted@gmail.com>
Date: Thu, 28 Sep 2023 16:44:29 +0900
Subject: [PATCH 12/12] snake-case

---
 src/graphnet/data/dataconverter.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 0f12e7ab5..41cec5eec 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -108,7 +108,7 @@ def __init__(
         workers: int = 1,
         index_column: str = "event_no",
         icetray_verbose: int = 0,
-        I3_Filters: List[I3Filter] = [],
+        i3_filters: List[I3Filter] = [],
     ):
         """Construct DataConverter.
 
@@ -170,9 +170,9 @@ def __init__(
         self._workers = workers
 
         # I3Filters (NullSplitI3Filter is always included)
-        self._I3Filters = [NullSplitI3Filter()] + I3_Filters
+        self._i3filters = [NullSplitI3Filter()] + i3_filters
 
-        for filter in self._I3Filters:
+        for filter in self._i3filters:
             assert isinstance(
                 filter, I3Filter
             ), f"{type(filter)} is not a subclass of I3Filter"
@@ -571,10 +571,10 @@ def _skip_frame(self, frame: "icetray.I3Frame") -> bool:
         Returns:
             bool: True if frame should be skipped, False otherwise.
         """
-        if self._I3Filters is None:
+        if self._i3filters is None:
             return False  # No filters defined, so we keep the frame
 
-        for filter in self._I3Filters:
+        for filter in self._i3filters:
             if not filter(frame):
                 return True  # keep_frame call false, skip the frame.
         return False  # All filter keep_frame calls true, keep the frame.