diff --git a/.github/contributors/tupui.md b/.github/contributors/tupui.md
new file mode 100644
index 000000000..5f53a72f8
--- /dev/null
+++ b/.github/contributors/tupui.md
@@ -0,0 +1,106 @@
+# spaCy contributor agreement
+
+This spaCy Contributor Agreement (**"SCA"**) is based on the
+[Oracle Contributor Agreement](http://www.oracle.com/technetwork/oca-405177.pdf).
+The SCA applies to any contribution that you make to any product or project
+managed by us (the **"project"**), and sets out the intellectual property rights
+you grant to us in the contributed materials. The term **"us"** shall mean
+[ExplosionAI GmbH](https://explosion.ai/legal). The term
+**"you"** shall mean the person or entity identified below.
+
+If you agree to be bound by these terms, fill in the information requested
+below and include the filled-in version with your first pull request, under the
+folder [`.github/contributors/`](/.github/contributors/). The name of the file
+should be your GitHub username, with the extension `.md`. For example, the user
+example_user would create the file `.github/contributors/example_user.md`.
+
+Read this agreement carefully before signing. These terms and conditions
+constitute a binding legal agreement.
+
+## Contributor Agreement
+
+1. The term "contribution" or "contributed materials" means any source code,
+object code, patch, tool, sample, graphic, specification, manual,
+documentation, or any other material posted or submitted by you to the project.
+
+2. With respect to any worldwide copyrights, or copyright applications and
+registrations, in your contribution:
+
+    * you hereby assign to us joint ownership, and to the extent that such
+    assignment is or becomes invalid, ineffective or unenforceable, you hereby
+    grant to us a perpetual, irrevocable, non-exclusive, worldwide, no-charge,
+    royalty-free, unrestricted license to exercise all rights under those
+    copyrights. This includes, at our option, the right to sublicense these same
+    rights to third parties through multiple levels of sublicensees or other
+    licensing arrangements;
+
+    * you agree that each of us can do all things in relation to your
+    contribution as if each of us were the sole owners, and if one of us makes
+    a derivative work of your contribution, the one who makes the derivative
+    work (or has it made will be the sole owner of that derivative work;
+
+    * you agree that you will not assert any moral rights in your contribution
+    against us, our licensees or transferees;
+
+    * you agree that we may register a copyright in your contribution and
+    exercise all ownership rights associated with it; and
+
+    * you agree that neither of us has any duty to consult with, obtain the
+    consent of, pay or render an accounting to the other for any use or
+    distribution of your contribution.
+
+3. With respect to any patents you own, or that you can license without payment
+to any third party, you hereby grant to us a perpetual, irrevocable,
+non-exclusive, worldwide, no-charge, royalty-free license to:
+
+    * make, have made, use, sell, offer to sell, import, and otherwise transfer
+    your contribution in whole or in part, alone or in combination with or
+    included in any product, work or materials arising out of the project to
+    which your contribution was submitted, and
+
+    * at our option, to sublicense these same rights to third parties through
+    multiple levels of sublicensees or other licensing arrangements.
+
+4. Except as set out above, you keep all right, title, and interest in your
+contribution. The rights that you grant to us under these terms are effective
+on the date you first submitted a contribution to us, even if your submission
+took place before the date you sign these terms.
+
+5. You covenant, represent, warrant and agree that:
+
+    * Each contribution that you submit is and shall be an original work of
+    authorship and you can legally grant the rights set out in this SCA;
+
+    * to the best of your knowledge, each contribution will not violate any
+    third party's copyrights, trademarks, patents, or other intellectual
+    property rights; and
+
+    * each contribution shall be in compliance with U.S. export control laws and
+    other applicable export and import laws. You agree to notify us if you
+    become aware of any circumstance which would make any of the foregoing
+    representations inaccurate in any respect. We may publicly disclose your
+    participation in the project, including the fact that you have signed the SCA.
+
+6. This SCA is governed by the laws of the State of California and applicable
+U.S. Federal law. Any choice of law rules will not apply.
+
+7. Please place an “x” on one of the applicable statement below. Please do NOT
+mark both statements:
+
+    * [x] I am signing on behalf of myself as an individual and no other person
+    or entity, including my employer, has or will have rights with respect to my
+    contributions.
+
+    * [ ] I am signing on behalf of my employer or a legal entity and I have the
+    actual authority to contractually bind that entity.
+
+## Contributor Details
+
+| Field                          | Entry                |
+|------------------------------- | -------------------- |
+| Name                           |     Pamphile Roy     |
+| Company name (if applicable)   |         N/A          |
+| Title or role (if applicable)  |         N/A          |
+| Date                           | January 29th, 2021   |
+| GitHub username                |         tupui        |
+| Website (optional)             |         N/A          |
diff --git a/requirements.txt b/requirements.txt
index 3cb30597a..c01399907 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,7 +24,7 @@ importlib_metadata>=0.20; python_version < "3.8"
 typing_extensions>=3.7.4; python_version < "3.8"
 # Development dependencies
 cython>=0.25
-pytest>=4.6.5
+pytest>=5.2.0
 pytest-timeout>=1.3.0,<2.0.0
 mock>=2.0.0,<3.0.0
 flake8>=3.5.0,<3.6.0
diff --git a/spacy/cli/download.py b/spacy/cli/download.py
index a7ebbfd77..75f68373d 100644
--- a/spacy/cli/download.py
+++ b/spacy/cli/download.py
@@ -105,8 +105,6 @@ def download_model(
     filename: str, user_pip_args: Optional[Sequence[str]] = None
 ) -> None:
     download_url = about.__download_url__ + "/" + filename
-    pip_args = ["--no-cache-dir"]
-    if user_pip_args:
-        pip_args.extend(user_pip_args)
+    pip_args = user_pip_args if user_pip_args is not None else []
     cmd = [sys.executable, "-m", "pip", "install"] + pip_args + [download_url]
     run_command(cmd)
diff --git a/spacy/cli/info.py b/spacy/cli/info.py
index 64d597890..16404a6a0 100644
--- a/spacy/cli/info.py
+++ b/spacy/cli/info.py
@@ -105,12 +105,15 @@ def info_model(model: str, *, silent: bool = True) -> Dict[str, Any]:
 
 
 def get_markdown(
-    data: Dict[str, Any], title: Optional[str] = None, exclude: Optional[List[str]] = None
+    data: Dict[str, Any],
+    title: Optional[str] = None,
+    exclude: Optional[List[str]] = None,
 ) -> str:
     """Get data in GitHub-flavoured Markdown format for issues etc.
 
-    data (dict or list of tuples): Label/value pairs.
-    title (str / None): Title, will be rendered as headline 2.
+    data (Dict[str, Any]): Label/value pairs.
+    title (str): Optional title, will be rendered as headline 2.
+    exclude (List[str]): Names of keys to exclude.
     RETURNS (str): The Markdown string.
     """
     md = MarkdownRenderer()
diff --git a/spacy/errors.py b/spacy/errors.py
index 6874f9a0c..f16f4fd9d 100644
--- a/spacy/errors.py
+++ b/spacy/errors.py
@@ -78,7 +78,7 @@ class Warnings:
     W035 = ('Discarding subpattern "{pattern}" due to an unrecognized '
             "attribute or operator.")
 
-    # TODO: fix numbering after merging develop into master
+    # New warnings added in v3.x
     W086 = ("Component '{listener}' will be (re)trained, but it needs the component "
             "'{name}' which is frozen. You can either freeze both, or neither "
             "of the two. If you're sourcing the component from "
@@ -483,8 +483,9 @@ class Errors:
     E199 = ("Unable to merge 0-length span at `doc[{start}:{end}]`.")
     E200 = ("Can't yet set {attr} from Span. Vote for this feature on the "
             "issue tracker: http://github.com/explosion/spaCy/issues")
+    E202 = ("Unsupported alignment mode '{mode}'. Supported modes: {modes}.")
 
-    # TODO: fix numbering after merging develop into master
+    # New errors added in v3.x
     E886 = ("Can't replace {name} -> {tok2vec} listeners: path '{path}' not "
             "found in config for component '{name}'.")
     E887 = ("Can't replace {name} -> {tok2vec} listeners: the paths to replace "
diff --git a/spacy/lang/es/__init__.py b/spacy/lang/es/__init__.py
index a0230b850..4b329b6f7 100644
--- a/spacy/lang/es/__init__.py
+++ b/spacy/lang/es/__init__.py
@@ -29,7 +29,9 @@ class Spanish(Language):
     default_config={"model": None, "mode": "rule", "overwrite": False},
     default_score_weights={"lemma_acc": 1.0},
 )
-def make_lemmatizer(nlp: Language, model: Optional[Model], name: str, mode: str, overwrite: bool):
+def make_lemmatizer(
+    nlp: Language, model: Optional[Model], name: str, mode: str, overwrite: bool
+):
     return SpanishLemmatizer(nlp.vocab, model, name, mode=mode, overwrite=overwrite)
 
 
diff --git a/spacy/lang/ky/tokenizer_exceptions.py b/spacy/lang/ky/tokenizer_exceptions.py
index cd51c2714..8ec727ac1 100644
--- a/spacy/lang/ky/tokenizer_exceptions.py
+++ b/spacy/lang/ky/tokenizer_exceptions.py
@@ -47,6 +47,7 @@ for exc_data in [  # "etc." abbreviations
     {ORTH: "көч.", NORM: "көчөсү"},
     {ORTH: "м-н", NORM: "менен"},
     {ORTH: "б-ча", NORM: "боюнча"},
-]:    _exc[exc_data[ORTH]] = [exc_data]
+]:
+    _exc[exc_data[ORTH]] = [exc_data]
 
 TOKENIZER_EXCEPTIONS = update_exc(BASE_EXCEPTIONS, _exc)
diff --git a/spacy/lang/lt/punctuation.py b/spacy/lang/lt/punctuation.py
index 506aa8f32..22aee0941 100644
--- a/spacy/lang/lt/punctuation.py
+++ b/spacy/lang/lt/punctuation.py
@@ -19,7 +19,7 @@ _infixes = (
 )
 
 
-_suffixes = ["\."] + list(TOKENIZER_SUFFIXES)
+_suffixes = [r"\."] + list(TOKENIZER_SUFFIXES)
 
 
 TOKENIZER_INFIXES = _infixes
diff --git a/spacy/lang/mk/lemmatizer.py b/spacy/lang/mk/lemmatizer.py
index ce3e73b7a..a792095e7 100644
--- a/spacy/lang/mk/lemmatizer.py
+++ b/spacy/lang/mk/lemmatizer.py
@@ -9,7 +9,6 @@ class MacedonianLemmatizer(Lemmatizer):
     def rule_lemmatize(self, token: Token) -> List[str]:
         string = token.text
         univ_pos = token.pos_.lower()
-        morphology = token.morph.to_dict()
 
         if univ_pos in ("", "eol", "space"):
             return [string.lower()]
diff --git a/spacy/language.py b/spacy/language.py
index eca311e8f..aab7c9b7a 100644
--- a/spacy/language.py
+++ b/spacy/language.py
@@ -1686,7 +1686,10 @@ class Language:
         return nlp
 
     def replace_listeners(
-        self, tok2vec_name: str, pipe_name: str, listeners: Iterable[str],
+        self,
+        tok2vec_name: str,
+        pipe_name: str,
+        listeners: Iterable[str],
     ) -> None:
         """Find listener layers (connecting to a token-to-vector embedding
         component) of a given pipeline component model and replace
diff --git a/spacy/pipeline/attributeruler.py b/spacy/pipeline/attributeruler.py
index 3d7d81c70..5e2278b5f 100644
--- a/spacy/pipeline/attributeruler.py
+++ b/spacy/pipeline/attributeruler.py
@@ -135,7 +135,6 @@ class AttributeRuler(Pipe):
                 ) from None
             set_token_attrs(span[index], attrs)
 
-
     def load_from_tag_map(
         self, tag_map: Dict[str, Dict[Union[int, str], Union[int, str]]]
     ) -> None:
diff --git a/spacy/pipeline/entity_linker.py b/spacy/pipeline/entity_linker.py
index 09debc993..5f4420233 100644
--- a/spacy/pipeline/entity_linker.py
+++ b/spacy/pipeline/entity_linker.py
@@ -217,7 +217,6 @@ class EntityLinker(TrainablePipe):
             return losses
         validate_examples(examples, "EntityLinker.update")
         sentence_docs = []
-        docs = [eg.predicted for eg in examples]
         for eg in examples:
             sentences = [s for s in eg.reference.sents]
             kb_ids = eg.get_aligned("ENT_KB_ID", as_string=True)
diff --git a/spacy/pipeline/functions.py b/spacy/pipeline/functions.py
index d955e970d..b233d1623 100644
--- a/spacy/pipeline/functions.py
+++ b/spacy/pipeline/functions.py
@@ -1,10 +1,9 @@
-import srsly
-from thinc.api import Config
 from typing import Dict, Any
+import srsly
+
 from ..language import Language
 from ..matcher import Matcher
 from ..tokens import Doc
-from ..util import filter_spans
 from .. import util
 
 
@@ -64,7 +63,7 @@ def merge_subtokens(doc: Doc, label: str = "subtok") -> Doc:
     merger = Matcher(doc.vocab)
     merger.add("SUBTOK", [[{"DEP": label, "op": "+"}]])
     matches = merger(doc)
-    spans = filter_spans([doc[start : end + 1] for _, start, end in matches])
+    spans = util.filter_spans([doc[start : end + 1] for _, start, end in matches])
     with doc.retokenize() as retokenizer:
         for span in spans:
             retokenizer.merge(span)
@@ -77,15 +76,9 @@ def merge_subtokens(doc: Doc, label: str = "subtok") -> Doc:
     retokenizes=True,
 )
 def make_token_splitter(
-    nlp: Language,
-    name: str,
-    *,
-    min_length=0,
-    split_length=0,
+    nlp: Language, name: str, *, min_length=0, split_length=0,
 ):
-    return TokenSplitter(
-        min_length=min_length, split_length=split_length
-    )
+    return TokenSplitter(min_length=min_length, split_length=split_length)
 
 
 class TokenSplitter:
diff --git a/spacy/pipeline/lemmatizer.py b/spacy/pipeline/lemmatizer.py
index d70c5867c..07d5b4af1 100644
--- a/spacy/pipeline/lemmatizer.py
+++ b/spacy/pipeline/lemmatizer.py
@@ -1,5 +1,4 @@
-from typing import Optional, List, Dict, Any, Callable, Iterable, Iterator, Union
-from typing import Tuple
+from typing import Optional, List, Dict, Any, Callable, Iterable, Union, Tuple
 from thinc.api import Model
 from pathlib import Path
 
diff --git a/spacy/tests/doc/test_doc_api.py b/spacy/tests/doc/test_doc_api.py
index ea95ca772..3ccdcc228 100644
--- a/spacy/tests/doc/test_doc_api.py
+++ b/spacy/tests/doc/test_doc_api.py
@@ -641,7 +641,8 @@ def test_doc_noun_chunks_not_implemented():
     nlp = MultiLanguage()
     doc = nlp(text)
     with pytest.raises(NotImplementedError):
-        chunks = list(doc.noun_chunks)
+        _ = list(doc.noun_chunks)  # noqa: F841
+
 
 def test_span_groups(en_tokenizer):
     doc = en_tokenizer("Some text about Colombia and the Czech Republic")
diff --git a/spacy/tests/doc/test_span.py b/spacy/tests/doc/test_span.py
index 4c7f0c86b..078cc81b1 100644
--- a/spacy/tests/doc/test_span.py
+++ b/spacy/tests/doc/test_span.py
@@ -195,6 +195,12 @@ def test_spans_by_character(doc):
     assert span1.end_char == span2.end_char
     assert span2.label_ == "GPE"
 
+    # unsupported alignment mode
+    with pytest.raises(ValueError):
+        span2 = doc.char_span(
+            span1.start_char + 1, span1.end_char, label="GPE", alignment_mode="unk"
+        )
+
 
 def test_span_to_array(doc):
     span = doc[1:-2]
diff --git a/spacy/tests/lang/ky/test_tokenizer.py b/spacy/tests/lang/ky/test_tokenizer.py
index 99dab2b16..91a048764 100644
--- a/spacy/tests/lang/ky/test_tokenizer.py
+++ b/spacy/tests/lang/ky/test_tokenizer.py
@@ -18,9 +18,7 @@ PUNC_INSIDE_WORDS_TESTS = [
     ('То"кой', 'То " кой'.split()),
 ]
 
-MIXED_ORDINAL_NUMS_TESTS = [
-    ("Эртең 22-январь...", "Эртең 22 - январь ...".split())
-]
+MIXED_ORDINAL_NUMS_TESTS = [("Эртең 22-январь...", "Эртең 22 - январь ...".split())]
 
 ABBREV_TESTS = [
     ("Маселе б-ча эртең келет", "Маселе б-ча эртең келет".split()),
diff --git a/spacy/tests/matcher/test_dependency_matcher.py b/spacy/tests/matcher/test_dependency_matcher.py
index d7492aa67..a563ddaa2 100644
--- a/spacy/tests/matcher/test_dependency_matcher.py
+++ b/spacy/tests/matcher/test_dependency_matcher.py
@@ -2,7 +2,6 @@ import pytest
 import pickle
 import re
 import copy
-import logging
 from mock import Mock
 from spacy.matcher import DependencyMatcher
 from spacy.tokens import Doc
@@ -343,6 +342,5 @@ def test_dependency_matcher_long_matches(en_vocab, doc):
     ]
 
     matcher = DependencyMatcher(en_vocab)
-    logger = logging.getLogger("spacy")
     with pytest.raises(ValueError):
         matcher.add("pattern", [pattern])
diff --git a/spacy/tests/matcher/test_phrase_matcher.py b/spacy/tests/matcher/test_phrase_matcher.py
index e95bd5eba..c7a3fef7d 100644
--- a/spacy/tests/matcher/test_phrase_matcher.py
+++ b/spacy/tests/matcher/test_phrase_matcher.py
@@ -322,4 +322,4 @@ def test_phrase_matcher_deprecated(en_vocab):
 
 @pytest.mark.parametrize("attr", ["SENT_START", "IS_SENT_START"])
 def test_phrase_matcher_sent_start(en_vocab, attr):
-    matcher = PhraseMatcher(en_vocab, attr=attr)
+    _ = PhraseMatcher(en_vocab, attr=attr)  # noqa: F841
diff --git a/spacy/tests/pipeline/test_tok2vec.py b/spacy/tests/pipeline/test_tok2vec.py
index c6ac42dd2..ac5428de6 100644
--- a/spacy/tests/pipeline/test_tok2vec.py
+++ b/spacy/tests/pipeline/test_tok2vec.py
@@ -6,7 +6,6 @@ from spacy.pipeline.tok2vec import Tok2Vec, Tok2VecListener
 from spacy.vocab import Vocab
 from spacy.tokens import Doc
 from spacy.training import Example
-from spacy.training.initialize import init_nlp
 from spacy import util
 from spacy.lang.en import English
 from thinc.api import Config
diff --git a/spacy/tests/regression/test_issue6258.py b/spacy/tests/regression/test_issue6001-6500.py
similarity index 55%
rename from spacy/tests/regression/test_issue6258.py
rename to spacy/tests/regression/test_issue6001-6500.py
index 9ce9026c0..470b2f388 100644
--- a/spacy/tests/regression/test_issue6258.py
+++ b/spacy/tests/regression/test_issue6001-6500.py
@@ -1,6 +1,21 @@
-import pytest
+from spacy.util import filter_spans
 from pydantic import ValidationError
 from spacy.schemas import TokenPattern, TokenPatternSchema
+import pytest
+
+
+def test_issue6207(en_tokenizer):
+    doc = en_tokenizer("zero one two three four five six")
+
+    # Make spans
+    s1 = doc[:4]
+    s2 = doc[3:6]  # overlaps with s1
+    s3 = doc[5:7]  # overlaps with s2, not s1
+
+    result = filter_spans((s1, s2, s3))
+    assert s1 in result
+    assert s2 not in result
+    assert s3 in result
 
 
 def test_issue6258():
diff --git a/spacy/tests/regression/test_issue6207.py b/spacy/tests/regression/test_issue6207.py
deleted file mode 100644
index 9d8b047bf..000000000
--- a/spacy/tests/regression/test_issue6207.py
+++ /dev/null
@@ -1,15 +0,0 @@
-from spacy.util import filter_spans
-
-
-def test_issue6207(en_tokenizer):
-    doc = en_tokenizer("zero one two three four five six")
-
-    # Make spans
-    s1 = doc[:4]
-    s2 = doc[3:6]  # overlaps with s1
-    s3 = doc[5:7]  # overlaps with s2, not s1
-
-    result = filter_spans((s1, s2, s3))
-    assert s1 in result
-    assert s2 not in result
-    assert s3 in result
diff --git a/spacy/tests/regression/test_issue6815.py b/spacy/tests/regression/test_issue6815.py
index 7c888a314..7d523e00b 100644
--- a/spacy/tests/regression/test_issue6815.py
+++ b/spacy/tests/regression/test_issue6815.py
@@ -1,12 +1,11 @@
 import pytest
 from spacy.lang.en import English
-import numpy as np 
+import numpy as np
 
 
 @pytest.mark.parametrize(
-    "sentence, start_idx,end_idx,label", [
-        ('Welcome to Mumbai, my friend',11,17,'GPE')
-    ]
+    "sentence, start_idx,end_idx,label",
+    [("Welcome to Mumbai, my friend", 11, 17, "GPE")],
 )
 def test_char_span_label(sentence, start_idx, end_idx, label):
     nlp = English()
@@ -14,10 +13,9 @@ def test_char_span_label(sentence, start_idx, end_idx, label):
     span = doc[:].char_span(start_idx, end_idx, label=label)
     assert span.label_ == label
 
+
 @pytest.mark.parametrize(
-    "sentence, start_idx,end_idx,kb_id", [
-        ('Welcome to Mumbai, my friend',11,17,5)
-    ]
+    "sentence, start_idx,end_idx,kb_id", [("Welcome to Mumbai, my friend", 11, 17, 5)]
 )
 def test_char_span_kb_id(sentence, start_idx, end_idx, kb_id):
     nlp = English()
@@ -25,13 +23,13 @@ def test_char_span_kb_id(sentence, start_idx, end_idx, kb_id):
     span = doc[:].char_span(start_idx, end_idx, kb_id=kb_id)
     assert span.kb_id == kb_id
 
+
 @pytest.mark.parametrize(
-    "sentence, start_idx,end_idx,vector", [
-        ('Welcome to Mumbai, my friend',11,17,np.array([0.1,0.2,0.3]))
-    ]
+    "sentence, start_idx,end_idx,vector",
+    [("Welcome to Mumbai, my friend", 11, 17, np.array([0.1, 0.2, 0.3]))],
 )
 def test_char_span_vector(sentence, start_idx, end_idx, vector):
     nlp = English()
     doc = nlp(sentence)
     span = doc[:].char_span(start_idx, end_idx, vector=vector)
-    assert (span.vector == vector).all()
\ No newline at end of file
+    assert (span.vector == vector).all()
diff --git a/spacy/tests/test_language.py b/spacy/tests/test_language.py
index f1b4eba6e..bec85a1a2 100644
--- a/spacy/tests/test_language.py
+++ b/spacy/tests/test_language.py
@@ -186,6 +186,7 @@ def test_language_pipe_error_handler():
 
 def test_language_pipe_error_handler_custom(en_vocab):
     """Test the error handling of a custom component that has no pipe method"""
+
     @Language.component("my_evil_component")
     def evil_component(doc):
         if "2" in doc.text:
@@ -194,6 +195,7 @@ def test_language_pipe_error_handler_custom(en_vocab):
 
     def warn_error(proc_name, proc, docs, e):
         from spacy.util import logger
+
         logger.warning(f"Trouble with component {proc_name}.")
 
     nlp = English()
@@ -217,6 +219,7 @@ def test_language_pipe_error_handler_custom(en_vocab):
 
 def test_language_pipe_error_handler_pipe(en_vocab):
     """Test the error handling of a component's pipe method"""
+
     @Language.component("my_sentences")
     def perhaps_set_sentences(doc):
         if not doc.text.startswith("4"):
diff --git a/spacy/tokens/doc.pyx b/spacy/tokens/doc.pyx
index 489de2201..a40931720 100644
--- a/spacy/tokens/doc.pyx
+++ b/spacy/tokens/doc.pyx
@@ -525,8 +525,9 @@ cdef class Doc:
             label = self.vocab.strings.add(label)
         if not isinstance(kb_id, int):
             kb_id = self.vocab.strings.add(kb_id)
-        if alignment_mode not in ("strict", "contract", "expand"):
-            alignment_mode = "strict"
+        alignment_modes = ("strict", "contract", "expand")
+        if alignment_mode not in alignment_modes:
+            raise ValueError(Errors.E202.format(mode=alignment_mode, modes=", ".join(alignment_modes)))
         cdef int start = token_by_char(self.c, self.length, start_idx)
         if start < 0 or (alignment_mode == "strict" and start_idx != self[start].idx):
             return None