diff --git a/qurator/dinglehopper/flexible_character_accuracy.py b/qurator/dinglehopper/flexible_character_accuracy.py
index 2b9a56f..e81ef54 100644
--- a/qurator/dinglehopper/flexible_character_accuracy.py
+++ b/qurator/dinglehopper/flexible_character_accuracy.py
@@ -29,20 +29,16 @@ def flexible_character_accuracy(gt: str, ocr: str) -> Tuple[float, List["Match"]
     :return: Score between 0 and 1 and match objects.
     """
 
-    best_score = -float('inf')
+    best_score = -float("inf")
     best_matches = []
     # TODO: this should be configurable
-    combinations = product(range(15, 31, 5),
-                           range(0, 24, 3),
-                           range(0, 4, 1),
-                           range(0, 6, 1))
+    combinations = product(
+        range(15, 31, 5), range(0, 24, 3), range(0, 4, 1), range(0, 6, 1)
+    )
     # TODO: place to parallelize the algorithm
     for (edit_dist, length_diff, offset, length) in combinations:
         coef = Coefficients(
-            edit_dist=edit_dist,
-            length_diff=length_diff,
-            offset=offset,
-            length=length
+            edit_dist=edit_dist, length_diff=length_diff, offset=offset, length=length
         )
         # Steps 1 - 6 of the flexible character accuracy algorithm.
         matches = match_with_coefficients(gt, ocr, coef)
@@ -79,17 +75,21 @@ def match_with_coefficients(gt: str, ocr: str, coef: "Coefficients") -> List["Ma
 
     # Step 6 of the flexible character accuracy algorithm.
     # remaining lines are considered as deletes and inserts
-    deletes = [distance(line, Part(text="", line=line.line, start=line.start))
-               for line in gt_lines]
-    inserts = [distance(Part(text="", line=line.line, start=line.start), line)
-               for line in ocr_lines]
+    deletes = [
+        distance(line, Part(text="", line=line.line, start=line.start))
+        for line in gt_lines
+    ]
+    inserts = [
+        distance(Part(text="", line=line.line, start=line.start), line)
+        for line in ocr_lines
+    ]
 
     return [*matches, *deletes, *inserts]
 
 
-def match_longest_gt_lines(gt_lines: List["Part"],
-                           ocr_lines: List["Part"],
-                           coef: "Coefficients") -> Optional["Match"]:
+def match_longest_gt_lines(
+    gt_lines: List["Part"], ocr_lines: List["Part"], coef: "Coefficients"
+) -> Optional["Match"]:
     """Find the best match for the longest line(s) in ground truth.
 
     The longest lines in ground truth are matched against lines in ocr to find the
@@ -99,7 +99,7 @@ def match_longest_gt_lines(gt_lines: List["Part"],
 
     :return: Possible match object.
     """
-    best_score, best_match, best_gt, best_ocr = -float('inf'), None, None, None
+    best_score, best_match, best_gt, best_ocr = -float("inf"), None, None, None
     if not ocr_lines:
         return best_match
 
@@ -126,10 +126,9 @@ def match_longest_gt_lines(gt_lines: List["Part"],
     return best_match
 
 
-def match_gt_line(gt_line: "Part",
-                  ocr_lines: List["Part"],
-                  coef: "Coefficients") -> Tuple[Optional["Match"],
-                                                 Optional["Part"]]:
+def match_gt_line(
+    gt_line: "Part", ocr_lines: List["Part"], coef: "Coefficients"
+) -> Tuple[Optional["Match"], Optional["Part"]]:
     """Match the given ground truth line against all the lines in ocr.
 
     Reference: contains steps 3 of the flexible character accuracy algorithm.
@@ -138,19 +137,18 @@ def match_gt_line(gt_line: "Part",
 
     :return: Match object and the matched ocr line.
     """
-    min_penalty = float('inf')
+    min_penalty = float("inf")
     best_match, best_ocr = None, None
     for ocr_line in [*ocr_lines]:
         match = match_lines(gt_line, ocr_line)
-        penalty = calculate_penalty(gt_line, ocr_line, match, coef)
-        if penalty < min_penalty:
-            min_penalty, best_match, best_ocr = penalty, match, ocr_line
+        if match:
+            penalty = calculate_penalty(gt_line, ocr_line, match, coef)
+            if penalty < min_penalty:
+                min_penalty, best_match, best_ocr = penalty, match, ocr_line
     return best_match, best_ocr
 
 
-def remove_or_split(original: "Part",
-                    match: "Part",
-                    lines: List["Part"]) -> bool:
+def remove_or_split(original: "Part", match: "Part", lines: List["Part"]) -> bool:
     """Removes the matched line or splits it into parts.
 
     Reference: contains step 4 of the flexible character accuracy algorithm.
@@ -187,17 +185,24 @@ def match_lines(gt_line: "Part", ocr_line: "Part") -> Optional["Match"]:
     if min_length == 0:
         return best_match
     length_diff = gt_line.length - ocr_line.length
-    min_edit_dist = float('inf')
+    min_edit_dist = float("inf")
 
-    gt_parts = [(i, gt_line.substring(rel_start=i, rel_end=i + min_length))
-                for i in range(0, max(1, length_diff + 1))]
-    ocr_parts = [(j, ocr_line.substring(rel_start=j, rel_end=j + min_length))
-                 for j in range(0, max(1, -1 * length_diff + 1))]
+    gt_parts = [
+        (i, gt_line.substring(rel_start=i, rel_end=i + min_length))
+        for i in range(0, max(1, length_diff + 1))
+    ]
+    ocr_parts = [
+        (j, ocr_line.substring(rel_start=j, rel_end=j + min_length))
+        for j in range(0, max(1, -1 * length_diff + 1))
+    ]
 
     # add full line and empty line match
     gt_parts = [*gt_parts, (0, gt_line), (0, gt_line)]
-    ocr_parts = [*ocr_parts, (0, ocr_line),
-                 (0, Part(text="", line=gt_line.line, start=gt_line.start))]
+    ocr_parts = [
+        *ocr_parts,
+        (0, ocr_line),
+        (0, Part(text="", line=gt_line.line, start=gt_line.start)),
+    ]
 
     for i, gt_part in gt_parts:
         for j, ocr_part in ocr_parts:
@@ -211,8 +216,10 @@ def match_lines(gt_line: "Part", ocr_line: "Part") -> Optional["Match"]:
         part_length = best_match.gt.length
         additional_length = best_match.dist.delete + best_match.dist.replace
         for k in range(part_length + 1, part_length + additional_length + 1):
-            match = distance(gt_line.substring(rel_start=best_i, rel_end=best_i + k),
-                             ocr_line.substring(rel_start=best_j, rel_end=best_j + k))
+            match = distance(
+                gt_line.substring(rel_start=best_i, rel_end=best_i + k),
+                ocr_line.substring(rel_start=best_j, rel_end=best_j + k),
+            )
             edit_dist = score_edit_distance(match)
             if edit_dist < min_edit_dist:
                 min_edit_dist = edit_dist
@@ -247,8 +254,9 @@ def score_edit_distance(match: "Match") -> int:
     return match.dist.delete + match.dist.insert + 2 * match.dist.replace
 
 
-def calculate_penalty(gt: "Part", ocr: "Part", match: "Match",
-                      coef: "Coefficients") -> float:
+def calculate_penalty(
+    gt: "Part", ocr: "Part", match: "Match", coef: "Coefficients"
+) -> float:
     """Calculate the penalty for a given match.
 
     For details and discussion see Section 3 in doi:10.1016/j.patrec.2020.02.003.
@@ -262,10 +270,12 @@ def calculate_penalty(gt: "Part", ocr: "Part", match: "Match",
     if length_diff > 1:
         substring_pos = max(match.gt.start - gt.start, match.ocr.start - ocr.start)
         offset = length_diff / 2 - abs(substring_pos - length_diff / 2)
-    return (min_edit_dist * coef.edit_dist
-            + length_diff * coef.length_diff
-            + offset * coef.offset
-            - substring_length * coef.length)
+    return (
+        min_edit_dist * coef.edit_dist
+        + length_diff * coef.length_diff
+        + offset * coef.offset
+        - substring_length * coef.length
+    )
 
 
 def character_accuracy_for_matches(matches: List["Match"]) -> float:
@@ -274,8 +284,9 @@ def character_accuracy_for_matches(matches: List["Match"]) -> float:
     See other `character_accuracy` for details.
 
     """
-    agg: Counter = reduce(lambda acc, match: acc + Counter(match.dist._asdict()),
-                          matches, Counter())
+    agg: Counter = reduce(
+        lambda acc, match: acc + Counter(match.dist._asdict()), matches, Counter()
+    )
 
     score = character_accuracy(Distance(**agg))
     return score
@@ -299,9 +310,9 @@ def character_accuracy(edits: "Distance") -> float:
     chars = edits.match + edits.replace + edits.delete
     if not chars and not errors:
         # comparison of empty strings is considered a full match
-        score = 1
+        score = 1.0
     else:
-        score = 1 - errors / chars
+        score = 1.0 - errors / chars
     return score
 
 
@@ -315,9 +326,11 @@ def initialize_lines(text: str) -> List["Part"]:
     :param text: Text to split into lines.
     :return: List of sorted line objects.
     """
-    lines = [Part(text=line, line=i, start=0)
-             for i, line in enumerate(text.splitlines())
-             if len(line) > 0]
+    lines = [
+        Part(text=line, line=i, start=0)
+        for i, line in enumerate(text.splitlines())
+        if len(line) > 0
+    ]
     lines.sort(key=lambda x: x.length, reverse=True)
     return lines
 
@@ -348,6 +361,7 @@ class Part(NamedTuple):
 
     This data object is maintained to be able to reproduce the original text.
     """
+
     text: str = ""
     line: int = 0
     start: int = 0
@@ -392,6 +406,7 @@ class Part(NamedTuple):
 
 class Distance(NamedTuple):
     """Represent distance between two sequences."""
+
     match: int = 0
     replace: int = 0
     delete: int = 0
@@ -400,6 +415,7 @@ class Distance(NamedTuple):
 
 class Match(NamedTuple):
     """Represent a calculated match between ground truth and the ocr result."""
+
     gt: "Part"
     ocr: "Part"
     dist: "Distance"
@@ -411,6 +427,7 @@ class Coefficients(NamedTuple):
 
     See Section 3 in doi:10.1016/j.patrec.2020.02.003
     """
+
     edit_dist: int = 25
     length_diff: int = 20
     offset: int = 1
diff --git a/qurator/dinglehopper/tests/test_flexible_character_accuracy.py b/qurator/dinglehopper/tests/test_flexible_character_accuracy.py
index 0126696..dfcb1f7 100644
--- a/qurator/dinglehopper/tests/test_flexible_character_accuracy.py
+++ b/qurator/dinglehopper/tests/test_flexible_character_accuracy.py
@@ -35,37 +35,31 @@ COMPLEX_CASES = [
 EXTENDED_CASES = [
     # See figure 4 in 10.1016/j.patrec.2020.02.003
     # A: No errors
-    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9),
-     (0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9),
-     1, 1),
+    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9), (0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9), 1, 1),
     # B: Different ordering of text blocks
-    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9),
-     (5, 6, 7, 8, 9, 11, 0, 1, 2, 3, 4),
-     1, 1),
+    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9), (5, 6, 7, 8, 9, 11, 0, 1, 2, 3, 4), 1, 1),
     # C: Merge across columns
-    ((0, 1, 2, 11, 3, 4, 11, 5, 6, 7, 11, 8, 9),
-     (0, 1, 2, 5, 6, 7, 11, 3, 4, 8, 9),
-     1, 0.964),
+    (
+        (0, 1, 2, 11, 3, 4, 11, 5, 6, 7, 11, 8, 9),
+        (0, 1, 2, 5, 6, 7, 11, 3, 4, 8, 9),
+        1,
+        0.964,
+    ),
     # D: Over-segmentation
-    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9),
-     (0, 1, 2, 11, 5, 6, 7, 11, 3, 4, 11, 8, 9),
-     1, 0.966),
+    (
+        (0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9),
+        (0, 1, 2, 11, 5, 6, 7, 11, 3, 4, 11, 8, 9),
+        1,
+        0.966,
+    ),
     # E: Part missing
-    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9),
-     (0, 1, 2, 3, 4),
-     1, 0.50),
+    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9), (0, 1, 2, 3, 4), 1, 0.50),
     # E.2: Part missing
-    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9),
-     (5, 6, 7, 8, 9),
-     1, 0.50),
+    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9), (5, 6, 7, 8, 9), 1, 0.50),
     # F: All missing
-    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9),
-     (),
-     1, 0),
+    ((0, 1, 2, 3, 4, 11, 5, 6, 7, 8, 9), (), 1, 0),
     # G: Added parts
-    ((0, 1, 2, 3, 4),
-     (0, 1, 2, 3, 4, 11, 5, 6),
-     1, 0.621),
+    ((0, 1, 2, 3, 4), (0, 1, 2, 3, 4, 11, 5, 6), 1, 0.621),
 ]
 
 EDIT_ARGS = "gt,ocr,expected_dist"
@@ -73,8 +67,11 @@ EDIT_ARGS = "gt,ocr,expected_dist"
 SIMPLE_EDITS = [
     (Part(text="a"), Part(text="a"), Distance(match=1)),
     (Part(text="aaa"), Part(text="aaa"), Distance(match=3)),
-    (Part(text="abcd"), Part(text="beed"),
-     Distance(match=2, replace=1, insert=1, delete=1)),
+    (
+        Part(text="abcd"),
+        Part(text="beed"),
+        Distance(match=2, replace=1, insert=1, delete=1),
+    ),
 ]
 
 
@@ -83,9 +80,20 @@ def extended_case_to_text(gt, ocr):
 
     See figure 4 in 10.1016/j.patrec.2020.02.003
     """
-    sentence = ("Eight", "happy", "frogs", "scuba", "dived",
-                "Jenny", "chick", "flaps", "white", "wings",
-                "", "\n")
+    sentence = (
+        "Eight",
+        "happy",
+        "frogs",
+        "scuba",
+        "dived",
+        "Jenny",
+        "chick",
+        "flaps",
+        "white",
+        "wings",
+        "",
+        "\n",
+    )
 
     gt_sentence = " ".join(sentence[i] for i in gt).replace(" \n ", "\n")
     ocr_sentence = " ".join(sentence[i] for i in ocr).replace(" \n ", "\n")
@@ -98,22 +106,35 @@ def test_flexible_character_accuracy_simple(gt, ocr, first_line_score, all_line_
     assert score == pytest.approx(all_line_score)
 
 
-@pytest.mark.parametrize("config,ocr", [
-    ("Config I",
-     "1 hav\nnospecial\ntalents.\nI am one\npassionate\ncuriousity.\"\nAlberto\nEmstein"
-     ),
-    ("Config II",
-     "1 hav\nnospecial\ntalents. Alberto\nI am one Emstein\npassionate\ncuriousity.\""
-     ),
-    ("Config III",
-     "Alberto\nEmstein\n1 hav\nnospecial\ntalents.\nI am one\npassionate\ncuriousity.\""
-     ),
-])
+@pytest.mark.parametrize(
+    "config,ocr",
+    [
+        (
+            "Config I",
+            "1 hav\nnospecial\ntalents.\n"
+            'I am one\npassionate\ncuriousity."\n'
+            "Alberto\nEmstein",
+        ),
+        (
+            "Config II",
+            '1 hav\nnospecial\ntalents. Alberto\n'
+            'I am one Emstein\npassionate\ncuriousity."',
+        ),
+        (
+            "Config III",
+            'Alberto\nEmstein\n'
+            '1 hav\nnospecial\ntalents.\n'
+            'I am one\npassionate\ncuriousity."',
+        ),
+    ],
+)
 def test_flexible_character_accuracy(config, ocr):
     """Tests from figure 3 in the paper."""
-    gt = "\"I have\nno special\ntalent." \
-         "\nI am only\npassionately\ncurious.\"" \
-         "\nAlbert\nEinstein"
+    gt = (
+        '"I have\nno special\ntalent.\n'
+        'I am only\npassionately\ncurious."\n'
+        "Albert\nEinstein"
+    )
     replacements, inserts, deletes = 3, 5, 7
     chars = len(gt) - gt.count("\n")
     assert chars == 68
@@ -127,21 +148,27 @@ def test_flexible_character_accuracy(config, ocr):
         replacements += 1
         deletes -= 1
 
-    expected_dist = Distance(match=chars - deletes - replacements, replace=replacements,
-                             insert=inserts, delete=deletes)
+    expected_dist = Distance(
+        match=chars - deletes - replacements,
+        replace=replacements,
+        insert=inserts,
+        delete=deletes,
+    )
     expected_score = character_accuracy(expected_dist)
 
     result, matches = flexible_character_accuracy(gt, ocr)
-    agg = reduce(lambda acc, match: acc + Counter(match.dist._asdict()),
-                 matches, Counter())
+    agg = reduce(
+        lambda acc, match: acc + Counter(match.dist._asdict()), matches, Counter()
+    )
     dist = Distance(**agg)
     assert dist == expected_dist
     assert result == pytest.approx(expected_score, abs=0.0005)
 
 
 @pytest.mark.parametrize(CASE_ARGS, EXTENDED_CASES)
-def test_flexible_character_accuracy_extended(gt, ocr, first_line_score,
-                                              all_line_score):
+def test_flexible_character_accuracy_extended(
+    gt, ocr, first_line_score, all_line_score
+):
     """Tests from figure 4 in the paper."""
     gt_sentence, ocr_sentence = extended_case_to_text(gt, ocr)
     result, _ = flexible_character_accuracy(gt_sentence, ocr_sentence)
@@ -170,10 +197,13 @@ def test_match_longest_gt_lines(gt, ocr, first_line_score, all_line_score):
     assert score == pytest.approx(first_line_score)
 
 
-@pytest.mark.parametrize(CASE_ARGS, [
-    *SIMPLE_CASES,
-    ("accc", "a\nbb\nccc", 1.0, 1.0),
-])
+@pytest.mark.parametrize(
+    CASE_ARGS,
+    [
+        *SIMPLE_CASES,
+        ("accc", "a\nbb\nccc", 1.0, 1.0),
+    ],
+)
 def test_match_gt_line(gt, ocr, first_line_score, all_line_score):
     coef = Coefficients()
     gt_lines = initialize_lines(gt)
@@ -185,15 +215,22 @@ def test_match_gt_line(gt, ocr, first_line_score, all_line_score):
     assert score == pytest.approx(first_line_score)
 
 
-@pytest.mark.parametrize("original,match,expected_lines", [
-    (Part(), Part(), []),
-    (Part(text="abc"), Part(), [Part(text="abc")]),
-    (Part(text="abc"), Part("d"), [Part(text="bc", start=1)]),
-    (Part(text="abc"), Part("a", start=100), [Part(text="abc")]),
-    (Part(text="abc"), Part("a"), [Part(text="bc", start=1)]),
-    (Part(text="abc"), Part("b", start=1), [Part(text="a"), Part(text="c", start=2)]),
-    (Part(text="abc"), Part("c", start=2), [Part(text="ab")]),
-])
+@pytest.mark.parametrize(
+    "original,match,expected_lines",
+    [
+        (Part(), Part(), []),
+        (Part(text="abc"), Part(), [Part(text="abc")]),
+        (Part(text="abc"), Part("d"), [Part(text="bc", start=1)]),
+        (Part(text="abc"), Part("a", start=100), [Part(text="abc")]),
+        (Part(text="abc"), Part("a"), [Part(text="bc", start=1)]),
+        (
+            Part(text="abc"),
+            Part("b", start=1),
+            [Part(text="a"), Part(text="c", start=2)],
+        ),
+        (Part(text="abc"), Part("c", start=2), [Part(text="ab")]),
+    ],
+)
 def test_remove_or_split(original, match, expected_lines):
     lines = [original]
     splitted = remove_or_split(original, match, lines)
@@ -201,18 +238,29 @@ def test_remove_or_split(original, match, expected_lines):
     assert lines == expected_lines
 
 
-@pytest.mark.parametrize(EDIT_ARGS, [
-    *SIMPLE_EDITS,
-    (Part(text="a"), Part(text="b"), Distance(delete=1)),
-    (Part(text="aaa"), Part(text="bbb"), Distance(delete=3)),
-    (Part(text="aaabbbaaa"), Part(text="bbb"), Distance(match=3)),
-    (Part(text="bbb"), Part(text="aaabbbaaa"), Distance(match=3)),
-    (Part(text=""), Part(text=""), None),
-    (Part(text="abcd"), Part(text="acd"), Distance(match=3, delete=1)),
-    (Part(text="abc"), Part(text="abdc"), Distance(match=3, insert=1)),
-    (Part(text="aaabbbaaaddd"), Part(text="aaabcbaaa"), Distance(match=8, replace=1)),
-    (Part(text="aaabbbccc"), Part(text="aaabbbdddccc"), Distance(match=9, insert=3)),
-])
+@pytest.mark.parametrize(
+    EDIT_ARGS,
+    [
+        *SIMPLE_EDITS,
+        (Part(text="a"), Part(text="b"), Distance(delete=1)),
+        (Part(text="aaa"), Part(text="bbb"), Distance(delete=3)),
+        (Part(text="aaabbbaaa"), Part(text="bbb"), Distance(match=3)),
+        (Part(text="bbb"), Part(text="aaabbbaaa"), Distance(match=3)),
+        (Part(text=""), Part(text=""), None),
+        (Part(text="abcd"), Part(text="acd"), Distance(match=3, delete=1)),
+        (Part(text="abc"), Part(text="abdc"), Distance(match=3, insert=1)),
+        (
+            Part(text="aaabbbaaaddd"),
+            Part(text="aaabcbaaa"),
+            Distance(match=8, replace=1),
+        ),
+        (
+            Part(text="aaabbbccc"),
+            Part(text="aaabbbdddccc"),
+            Distance(match=9, insert=3),
+        ),
+    ],
+)
 def test_match_lines(gt, ocr, expected_dist):
     match = match_lines(gt, ocr)
     if not expected_dist:
@@ -223,14 +271,17 @@ def test_match_lines(gt, ocr, expected_dist):
         assert match.dist == expected_dist
 
 
-@pytest.mark.parametrize(EDIT_ARGS, [
-    *SIMPLE_EDITS,
-    (Part(text="").substring(), Part(text=""), Distance()),
-    (Part(text="ab").substring(), Part("a"), Distance(match=1, delete=1)),
-    (Part(text="a").substring(), Part("ab"), Distance(match=1, insert=1)),
-    (Part(text="a"), Part(text="b"), Distance(replace=1)),
-    (Part(text="aaa"), Part(text="bbb"), Distance(replace=3)),
-])
+@pytest.mark.parametrize(
+    EDIT_ARGS,
+    [
+        *SIMPLE_EDITS,
+        (Part(text="").substring(), Part(text=""), Distance()),
+        (Part(text="ab").substring(), Part("a"), Distance(match=1, delete=1)),
+        (Part(text="a").substring(), Part("ab"), Distance(match=1, insert=1)),
+        (Part(text="a"), Part(text="b"), Distance(replace=1)),
+        (Part(text="aaa"), Part(text="bbb"), Distance(replace=3)),
+    ],
+)
 def test_distance(gt, ocr, expected_dist):
     match = distance(gt, ocr)
     assert match.gt == gt
@@ -238,46 +289,77 @@ def test_distance(gt, ocr, expected_dist):
     assert match.dist == expected_dist
 
 
-@pytest.mark.parametrize("matches,expected_dist", [
-    ([], 1),
-    ([Match(gt=Part(text=""), ocr=Part(text=""), dist=Distance(), ops=[])], 1),
-    ([Match(gt=Part(text="abee"), ocr=Part("ac"),
-            dist=Distance(match=1, replace=1, delete=2), ops=[]),
-      Match(gt=Part(text="cd"), ocr=Part("ceff"),
-            dist=Distance(match=1, replace=1, insert=2), ops=[])],
-     1 - 6 / 6),
-])
+@pytest.mark.parametrize(
+    "matches,expected_dist",
+    [
+        ([], 1),
+        ([Match(gt=Part(text=""), ocr=Part(text=""), dist=Distance(), ops=[])], 1),
+        (
+            [
+                Match(
+                    gt=Part(text="abee"),
+                    ocr=Part("ac"),
+                    dist=Distance(match=1, replace=1, delete=2),
+                    ops=[],
+                ),
+                Match(
+                    gt=Part(text="cd"),
+                    ocr=Part("ceff"),
+                    dist=Distance(match=1, replace=1, insert=2),
+                    ops=[],
+                ),
+            ],
+            1 - 6 / 6,
+        ),
+    ],
+)
 def test_character_accuracy_matches(matches, expected_dist):
     assert character_accuracy_for_matches(matches) == pytest.approx(expected_dist)
 
 
-@pytest.mark.parametrize("dist,expected_dist", [
-    (Distance(), 1),
-    (Distance(match=1), 1),
-    (Distance(replace=1), 0),
-    (Distance(match=1, insert=1), 0),
-    (Distance(match=1, insert=2), 1 - 2 / 1),
-    (Distance(match=2, insert=1), 0.5),
-    (Distance(match=1, delete=1), 0.5),
-])
+@pytest.mark.parametrize(
+    "dist,expected_dist",
+    [
+        (Distance(), 1),
+        (Distance(match=1), 1),
+        (Distance(replace=1), 0),
+        (Distance(match=1, insert=1), 0),
+        (Distance(match=1, insert=2), 1 - 2 / 1),
+        (Distance(match=2, insert=1), 0.5),
+        (Distance(match=1, delete=1), 0.5),
+    ],
+)
 def test_character_accuracy_dist(dist, expected_dist):
     assert character_accuracy(dist) == pytest.approx(expected_dist)
 
 
-@pytest.mark.parametrize("line,subline,expected_rest", [
-    (Part(), Part(), []),
-    (Part("aaa bbb"), Part("aaa bbb"), []),
-    (Part("aaa bbb"), Part("aaa"), [Part(" bbb", start=3)]),
-    (Part("aaa bbb"), Part("bbb", start=4), [Part("aaa ")]),
-    (Part("aaa bbb", start=3), Part("aaa", start=3), [Part(" bbb", start=6)]),
-    (Part("aaa bbb", start=3), Part("bbb", start=7), [Part("aaa ", start=3)]),
-    (Part("aaa bbb ccc"), Part("bbb", start=4), [Part("aaa "), Part(" ccc", start=7)]),
-    (Part("aaa bbb ccc", start=3), Part("bbb", start=7),
-     [Part("aaa ", start=3), Part(" ccc", start=10)]),
-    (Part("aaa bbb"), Part(" ", start=3), [Part("aaa"), Part("bbb", start=4)]),
-    (Part("aaa bbb", start=3), Part(" ", start=6),
-     [Part("aaa", start=3), Part("bbb", start=7)]),
-])
+@pytest.mark.parametrize(
+    "line,subline,expected_rest",
+    [
+        (Part(), Part(), []),
+        (Part("aaa bbb"), Part("aaa bbb"), []),
+        (Part("aaa bbb"), Part("aaa"), [Part(" bbb", start=3)]),
+        (Part("aaa bbb"), Part("bbb", start=4), [Part("aaa ")]),
+        (Part("aaa bbb", start=3), Part("aaa", start=3), [Part(" bbb", start=6)]),
+        (Part("aaa bbb", start=3), Part("bbb", start=7), [Part("aaa ", start=3)]),
+        (
+            Part("aaa bbb ccc"),
+            Part("bbb", start=4),
+            [Part("aaa "), Part(" ccc", start=7)],
+        ),
+        (
+            Part("aaa bbb ccc", start=3),
+            Part("bbb", start=7),
+            [Part("aaa ", start=3), Part(" ccc", start=10)],
+        ),
+        (Part("aaa bbb"), Part(" ", start=3), [Part("aaa"), Part("bbb", start=4)]),
+        (
+            Part("aaa bbb", start=3),
+            Part(" ", start=6),
+            [Part("aaa", start=3), Part("bbb", start=7)],
+        ),
+    ],
+)
 def test_split_line(line, subline, expected_rest):
     rest = line.split(subline)
     assert len(rest) == len(expected_rest)
@@ -300,12 +382,15 @@ def test_combine_lines():
     assert False
 
 
-@pytest.mark.parametrize("line,start,end,expected", [
-    (Part(text=""), 0, None, Part(text="")),
-    (Part(text="a"), 0, None, Part(text="a")),
-    (Part(text="ab"), 0, 1, Part(text="a")),
-    (Part(text="abc"), 0, -1, Part(text="ab")),
-    (Part(text="ab"), 1, None, Part(text="b", start=1)),
-])
+@pytest.mark.parametrize(
+    "line,start,end,expected",
+    [
+        (Part(text=""), 0, None, Part(text="")),
+        (Part(text="a"), 0, None, Part(text="a")),
+        (Part(text="ab"), 0, 1, Part(text="a")),
+        (Part(text="abc"), 0, -1, Part(text="ab")),
+        (Part(text="ab"), 1, None, Part(text="b", start=1)),
+    ],
+)
 def test_line_substring(line, start, end, expected):
     assert line.substring(rel_start=start, rel_end=end) == expected