Merge branch 'develop' into spacy.io

.github/contributors/tmetzl.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 UG (haftungsbeschränkt)](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                           | Tim Metzler          |
+| Company name (if applicable)   | University of Applied Sciences Bonn-Rhein-Sieg |
+| Title or role (if applicable)  |                      |
+| Date                           | 03/10/2019           |
+| GitHub username                | tmetzl               |
+| Website (optional)             |                      |

spacy/tests/doc/test_underscore.py

@@ -106,3 +106,37 @@ def test_underscore_raises_for_invalid(invalid_kwargs):
 def test_underscore_accepts_valid(valid_kwargs):
     valid_kwargs["force"] = True
     Doc.set_extension("test", **valid_kwargs)
+
+
+def test_underscore_mutable_defaults_list(en_vocab):
+    """Test that mutable default arguments are handled correctly (see #2581)."""
+    Doc.set_extension("mutable", default=[])
+    doc1 = Doc(en_vocab, words=["one"])
+    doc2 = Doc(en_vocab, words=["two"])
+    doc1._.mutable.append("foo")
+    assert len(doc1._.mutable) == 1
+    assert doc1._.mutable[0] == "foo"
+    assert len(doc2._.mutable) == 0
+    doc1._.mutable = ["bar", "baz"]
+    doc1._.mutable.append("foo")
+    assert len(doc1._.mutable) == 3
+    assert len(doc2._.mutable) == 0
+
+
+def test_underscore_mutable_defaults_dict(en_vocab):
+    """Test that mutable default arguments are handled correctly (see #2581)."""
+    Token.set_extension("mutable", default={})
+    token1 = Doc(en_vocab, words=["one"])[0]
+    token2 = Doc(en_vocab, words=["two"])[0]
+    token1._.mutable["foo"] = "bar"
+    assert len(token1._.mutable) == 1
+    assert token1._.mutable["foo"] == "bar"
+    assert len(token2._.mutable) == 0
+    token1._.mutable["foo"] = "baz"
+    assert len(token1._.mutable) == 1
+    assert token1._.mutable["foo"] == "baz"
+    token1._.mutable["x"] = []
+    token1._.mutable["x"].append("y")
+    assert len(token1._.mutable) == 2
+    assert token1._.mutable["x"] == ["y"]
+    assert len(token2._.mutable) == 0

spacy/tokens/underscore.py

@@ -2,11 +2,13 @@
 from __future__ import unicode_literals
 
 import functools
+import copy
 
 from ..errors import Errors
 
 
 class Underscore(object):
+    mutable_types = (dict, list, set)
     doc_extensions = {}
     span_extensions = {}
     token_extensions = {}
@@ -32,7 +34,15 @@ class Underscore(object):
         elif method is not None:
             return functools.partial(method, self._obj)
         else:
-            return self._doc.user_data.get(self._get_key(name), default)
+            key = self._get_key(name)
+            if key in self._doc.user_data:
+                return self._doc.user_data[key]
+            elif isinstance(default, self.mutable_types):
+                # Handle mutable default arguments (see #2581)
+                new_default = copy.copy(default)
+                self.__setattr__(name, new_default)
+                return new_default
+            return default
 
     def __setattr__(self, name, value):
         if name not in self._extensions:

website/docs/usage/processing-pipelines.md

@@ -458,9 +458,7 @@ There are three main types of extensions, which can be defined using the
 1. **Attribute extensions.** Set a default value for an attribute, which can be
    overwritten manually at any time. Attribute extensions work like "normal"
    variables and are the quickest way to store arbitrary information on a `Doc`,
-   `Span` or `Token`. Attribute defaults behaves just like argument defaults
-   [in Python functions](http://docs.python-guide.org/en/latest/writing/gotchas/#mutable-default-arguments),
-   and should not be used for mutable values like dictionaries or lists.
+   `Span` or `Token`.
 
    ```python
     Doc.set_extension("hello", default=True)
@@ -527,25 +525,6 @@ Once you've registered your custom attribute, you can also use the built-in
 especially useful it you want to pass in a string instead of calling
 `doc._.my_attr`.
 
-<Infobox title="Using mutable default values" variant="danger">
-
-When using **mutable values** like dictionaries or lists as the `default`
-argument, keep in mind that they behave just like mutable default arguments
-[in Python functions](http://docs.python-guide.org/en/latest/writing/gotchas/#mutable-default-arguments).
-This can easily cause unintended results, like the same value being set on _all_
-objects instead of only one particular instance. In most cases, it's better to
-use **getters and setters**, and only set the `default` for boolean or string
-values.
-
-```diff
-+ Doc.set_extension('fruits', getter=get_fruits, setter=set_fruits)
-
-- Doc.set_extension('fruits', default={})
-- doc._.fruits['apple'] = u'🍎'  # all docs now have {'apple': u'🍎'}
-```
-
-</Infobox>
-
 ### Example: Pipeline component for GPE entities and country meta data via a REST API {#component-example3}
 
 This example shows the implementation of a pipeline component that fetches