docs: use __init__ method instead of constructor

docs/conf.py

@@ -237,7 +237,7 @@
     r'\bContractsManager\b$',
 
     # For default contracts we only want to document their general purpose in
-    # their constructor, the methods they reimplement to achieve that purpose
+    # their __init__ method, the methods they reimplement to achieve that purpose
     # should be irrelevant to developers using those contracts.
     r'\w+Contract\.(adjust_request_args|(pre|post)_process)$',
 

docs/news.rst

@@ -84,12 +84,12 @@ New features
     convenient way to build JSON requests (:issue:`3504`, :issue:`3505`)
 
 *   A ``process_request`` callback passed to the :class:`~scrapy.spiders.Rule`
-    constructor now receives the :class:`~scrapy.http.Response` object that
+    ``__init__`` method now receives the :class:`~scrapy.http.Response` object that
     originated the request as its second argument (:issue:`3682`)
 
 *   A new ``restrict_text`` parameter for the
     :attr:`LinkExtractor <scrapy.linkextractors.lxmlhtml.LxmlLinkExtractor>`
-    constructor allows filtering links by linking text (:issue:`3622`,
+    ``__init__`` method allows filtering links by linking text (:issue:`3622`,
     :issue:`3635`)
 
 *   A new :setting:`FEED_STORAGE_S3_ACL` setting allows defining a custom ACL
@@ -255,7 +255,7 @@ The following deprecated APIs have been removed (:issue:`3578`):
 
 *   From :class:`~scrapy.selector.Selector`:
 
-    *   ``_root`` (both the constructor argument and the object property, use
+    *   ``_root`` (both the ``__init__`` method argument and the object property, use
         ``root``)
 
     *   ``extract_unquoted`` (use ``getall``)
@@ -2479,7 +2479,7 @@ Scrapy changes:
 - removed ``ENCODING_ALIASES`` setting, as encoding auto-detection has been moved to the `w3lib`_ library
 - promoted :ref:`topics-djangoitem` to main contrib
 - LogFormatter method now return dicts(instead of strings) to support lazy formatting (:issue:`164`, :commit:`dcef7b0`)
-- downloader handlers (:setting:`DOWNLOAD_HANDLERS` setting) now receive settings as the first argument of the constructor
+- downloader handlers (:setting:`DOWNLOAD_HANDLERS` setting) now receive settings as the first argument of the ``__init__`` method
 - replaced memory usage acounting with (more portable) `resource`_ module, removed ``scrapy.utils.memory`` module
 - removed signal: ``scrapy.mail.mail_sent``
 - removed ``TRACK_REFS`` setting, now :ref:`trackrefs <topics-leaks-trackrefs>` is always enabled
@@ -2693,7 +2693,7 @@ API changes
 - ``Request.copy()`` and ``Request.replace()`` now also copies their ``callback`` and ``errback`` attributes (#231)
 - Removed ``UrlFilterMiddleware`` from ``scrapy.contrib`` (already disabled by default)
 - Offsite middelware doesn't filter out any request coming from a spider that doesn't have a allowed_domains attribute (#225)
-- Removed Spider Manager ``load()`` method. Now spiders are loaded in the constructor itself.
+- Removed Spider Manager ``load()`` method. Now spiders are loaded in the ``__init__`` method itself.
 - Changes to Scrapy Manager (now called "Crawler"):
    - ``scrapy.core.manager.ScrapyManager`` class renamed to ``scrapy.crawler.Crawler``
    - ``scrapy.core.manager.scrapymanager`` singleton moved to ``scrapy.project.crawler``

docs/topics/email.rst

@@ -21,7 +21,7 @@ Quick example
 =============
 
 There are two ways to instantiate the mail sender. You can instantiate it using
-the standard constructor::
+the standard ``__init__`` method::
 
     from scrapy.mail import MailSender
     mailer = MailSender()
@@ -111,7 +111,7 @@ uses `Twisted non-blocking IO`_, like the rest of the framework.
 Mail settings
 =============
 
-These settings define the default constructor values of the :class:`MailSender`
+These settings define the default ``__init__`` method values of the :class:`MailSender`
 class, and can be used to configure e-mail notifications in your project without
 writing any code (for those extensions and code that uses :class:`MailSender`).
 

docs/topics/exporters.rst

@@ -87,8 +87,8 @@ described next.
 1. Declaring a serializer in the field
 --------------------------------------
 
-If you use :class:`~.Item` you can declare a serializer in the 
-:ref:`field metadata <topics-items-fields>`. The serializer must be 
+If you use :class:`~.Item` you can declare a serializer in the
+:ref:`field metadata <topics-items-fields>`. The serializer must be
 a callable which receives a value and returns its serialized form.
 
 Example::
@@ -144,7 +144,7 @@ BaseItemExporter
    defining what fields to export, whether to export empty fields, or which
    encoding to use.
 
-   These features can be configured through the constructor arguments which
+   These features can be configured through the ``__init__`` method arguments which
    populate their respective instance attributes: :attr:`fields_to_export`,
    :attr:`export_empty_fields`, :attr:`encoding`, :attr:`indent`.
 
@@ -246,8 +246,8 @@ XmlItemExporter
    :param item_element: The name of each item element in the exported XML.
    :type item_element: str
 
-   The additional keyword arguments of this constructor are passed to the
-   :class:`BaseItemExporter` constructor.
+   The additional keyword arguments of this ``__init__`` method are passed to the
+   :class:`BaseItemExporter` ``__init__`` method
 
    A typical output of this exporter would be::
 
@@ -306,9 +306,9 @@ CsvItemExporter
       multi-valued fields, if found.
    :type include_headers_line: str
 
-   The additional keyword arguments of this constructor are passed to the
-   :class:`BaseItemExporter` constructor, and the leftover arguments to the
-   `csv.writer`_ constructor, so you can use any ``csv.writer`` constructor
+   The additional keyword arguments of this ``__init__`` method are passed to the
+   :class:`BaseItemExporter` ``__init__`` method, and the leftover arguments to the
+   `csv.writer`_ ``__init__`` method, so you can use any ``csv.writer`` ``__init__`` method
    argument to customize this exporter.
 
    A typical output of this exporter would be::
@@ -334,8 +334,8 @@ PickleItemExporter
 
    For more information, refer to the `pickle module documentation`_.
 
-   The additional keyword arguments of this constructor are passed to the
-   :class:`BaseItemExporter` constructor.
+   The additional keyword arguments of this ``__init__`` method are passed to the
+   :class:`BaseItemExporter` ``__init__`` method.
 
    Pickle isn't a human readable format, so no output examples are provided.
 
@@ -351,8 +351,8 @@ PprintItemExporter
    :param file: the file-like object to use for exporting the data. Its ``write`` method should
                 accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
 
-   The additional keyword arguments of this constructor are passed to the
-   :class:`BaseItemExporter` constructor.
+   The additional keyword arguments of this ``__init__`` method are passed to the
+   :class:`BaseItemExporter` ``__init__`` method
 
    A typical output of this exporter would be::
 
@@ -367,10 +367,10 @@ JsonItemExporter
 .. class:: JsonItemExporter(file, \**kwargs)
 
    Exports Items in JSON format to the specified file-like object, writing all
-   objects as a list of objects. The additional constructor arguments are
-   passed to the :class:`BaseItemExporter` constructor, and the leftover
-   arguments to the `JSONEncoder`_ constructor, so you can use any
-   `JSONEncoder`_ constructor argument to customize this exporter.
+   objects as a list of objects. The additional ``__init__`` method arguments are
+   passed to the :class:`BaseItemExporter` ``__init__`` method, and the leftover
+   arguments to the `JSONEncoder`_ ``__init__`` method, so you can use any
+   `JSONEncoder`_ ``__init__`` method argument to customize this exporter.
 
    :param file: the file-like object to use for exporting the data. Its ``write`` method should
                 accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@@ -398,10 +398,10 @@ JsonLinesItemExporter
 .. class:: JsonLinesItemExporter(file, \**kwargs)
 
    Exports Items in JSON format to the specified file-like object, writing one
-   JSON-encoded item per line. The additional constructor arguments are passed
-   to the :class:`BaseItemExporter` constructor, and the leftover arguments to
-   the `JSONEncoder`_ constructor, so you can use any `JSONEncoder`_
-   constructor argument to customize this exporter.
+   JSON-encoded item per line. The additional ``__init__`` method arguments are passed
+   to the :class:`BaseItemExporter` ``__init__`` method and the leftover arguments to
+   the `JSONEncoder`_ ``__init__`` method, so you can use any `JSONEncoder`_
+   ``__init__`` method argument to customize this exporter.
 
    :param file: the file-like object to use for exporting the data. Its ``write`` method should
                 accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)

docs/topics/extensions.rst

@@ -28,7 +28,7 @@ Loading & activating extensions
 
 Extensions are loaded and activated at startup by instantiating a single
 instance of the extension class. Therefore, all the extension initialization
-code must be performed in the class constructor (``__init__`` method).
+code must be performed in the class ``__init__`` method.
 
 To make an extension available, add it to the :setting:`EXTENSIONS` setting in
 your Scrapy settings. In :setting:`EXTENSIONS`, each extension is represented

docs/topics/items.rst

@@ -16,12 +16,12 @@ especially in a larger project with many spiders.
 To define common output data format Scrapy provides the :class:`Item` class.
 :class:`Item` objects are simple containers used to collect the scraped data.
 They provide a `dictionary-like`_ API with a convenient syntax for declaring
-their available fields. 
+their available fields.
 
-Various Scrapy components use extra information provided by Items: 
+Various Scrapy components use extra information provided by Items:
 exporters look at declared fields to figure out columns to export,
 serialization can be customized using Item fields metadata, :mod:`trackref`
-tracks Item instances to help find memory leaks 
+tracks Item instances to help find memory leaks
 (see :ref:`topics-leaks-trackrefs`), etc.
 
 .. _dictionary-like: https://docs.python.org/2/library/stdtypes.html#dict
@@ -237,7 +237,7 @@ Item objects
 
     Return a new Item optionally initialized from the given argument.
 
-    Items replicate the standard `dict API`_, including its constructor, and
+    Items replicate the standard `dict API`_, including its ``__init__`` method and
     also provide the following additional API members:
 
     .. automethod:: copy

docs/topics/loaders.rst

@@ -26,7 +26,7 @@ Using Item Loaders to populate items
 
 To use an Item Loader, you must first instantiate it. You can either
 instantiate it with a dict-like object (e.g. Item or dict) or without one, in
-which case an Item is automatically instantiated in the Item Loader constructor
+which case an Item is automatically instantiated in the Item Loader ``__init__`` method
 using the Item class specified in the :attr:`ItemLoader.default_item_class`
 attribute.
 
@@ -265,7 +265,7 @@ There are several ways to modify Item Loader context values:
       loader.context['unit'] = 'cm'
 
 2. On Item Loader instantiation (the keyword arguments of Item Loader
-   constructor are stored in the Item Loader context)::
+   ``__init__`` methodare stored in the Item Loader context)::
 
       loader = ItemLoader(product, unit='cm')
 
@@ -494,7 +494,7 @@ ItemLoader objects
     .. attribute:: default_item_class
 
         An Item class (or factory), used to instantiate items when not given in
-        the constructor.
+        the ``__init__`` method
 
     .. attribute:: default_input_processor
 
@@ -509,15 +509,15 @@ ItemLoader objects
     .. attribute:: default_selector_class
 
         The class used to construct the :attr:`selector` of this
-        :class:`ItemLoader`, if only a response is given in the constructor.
-        If a selector is given in the constructor this attribute is ignored.
+        :class:`ItemLoader`, if only a response is given in the ``__init__`` method
+        If a selector is given in the ``__init__`` method this attribute is ignored.
         This attribute is sometimes overridden in subclasses.
 
     .. attribute:: selector
 
         The :class:`~scrapy.selector.Selector` object to extract data from.
-        It's either the selector given in the constructor or one created from
-        the response given in the constructor using the
+        It's either the selector given in the ``__init__`` methodor one created from
+        the response given in the ``__init__`` methodusing the
         :attr:`default_selector_class`. This attribute is meant to be
         read-only.
 
@@ -642,7 +642,7 @@ Here is a list of all built-in processors:
 .. class:: Identity
 
     The simplest processor, which doesn't do anything. It returns the original
-    values unchanged. It doesn't receive any constructor arguments, nor does it
+    values unchanged. It doesn't receive any ``__init__`` method arguments, nor does it
     accept Loader contexts.
 
     Example::
@@ -656,7 +656,7 @@ Here is a list of all built-in processors:
 
     Returns the first non-null/non-empty value from the values received,
     so it's typically used as an output processor to single-valued fields.
-    It doesn't receive any constructor arguments, nor does it accept Loader contexts.
+    It doesn't receive any ``__init__`` methodarguments, nor does it accept Loader contexts.
 
     Example::
 
@@ -667,7 +667,7 @@ Here is a list of all built-in processors:
 
 .. class:: Join(separator=u' ')
 
-    Returns the values joined with the separator given in the constructor, which
+    Returns the values joined with the separator given in the ``__init__`` method which
     defaults to ``u' '``. It doesn't accept Loader contexts.
 
     When using the default separator, this processor is equivalent to the
@@ -705,7 +705,7 @@ Here is a list of all built-in processors:
     those which do, this processor will pass the currently active :ref:`Loader
     context <topics-loaders-context>` through that parameter.
 
-    The keyword arguments passed in the constructor are used as the default
+    The keyword arguments passed in the ``__init__`` methodare used as the default
     Loader context values passed to each function call. However, the final
     Loader context values passed to functions are overridden with the currently
     active Loader context accessible through the :meth:`ItemLoader.context`
@@ -749,12 +749,12 @@ Here is a list of all built-in processors:
         ['HELLO, 'THIS', 'IS', 'SCRAPY']
 
     As with the Compose processor, functions can receive Loader contexts, and
-    constructor keyword arguments are used as default context values. See
+    ``__init__`` method keyword arguments are used as default context values. See
     :class:`Compose` processor for more info.
 
 .. class:: SelectJmes(json_path)
 
-    Queries the value using the json path provided to the constructor and returns the output.
+    Queries the value using the json path provided to the ``__init__`` methodand returns the output.
     Requires jmespath (https://github.com/jmespath/jmespath.py) to run.
     This processor takes only one input at a time.
 

docs/topics/request-response.rst

@@ -137,7 +137,7 @@ Request objects
 
         A string containing the URL of this request. Keep in mind that this
         attribute contains the escaped URL, so it can differ from the URL passed in
-        the constructor.
+        the ``__init__`` method
 
         This attribute is read-only. To change the URL of a Request use
         :meth:`replace`.
@@ -400,7 +400,7 @@ fields with form data from :class:`Response` objects.
 
 .. class:: FormRequest(url, [formdata, ...])
 
-    The :class:`FormRequest` class adds a new keyword parameter to the constructor. The
+    The :class:`FormRequest` class adds a new keyword parameter to the ``__init__`` method The
     remaining arguments are the same as for the :class:`Request` class and are
     not documented here.
 
@@ -473,7 +473,7 @@ fields with form data from :class:`Response` objects.
        :type dont_click: boolean
 
        The other parameters of this class method are passed directly to the
-       :class:`FormRequest` constructor.
+       :class:`FormRequest` ``__init__`` method
 
        .. versionadded:: 0.10.3
           The ``formname`` parameter.
@@ -547,7 +547,7 @@ dealing with JSON requests.
 
 .. class:: JsonRequest(url, [... data, dumps_kwargs])
 
-   The :class:`JsonRequest` class adds two new keyword parameters to the constructor. The
+   The :class:`JsonRequest` class adds two new keyword parameters to the ``__init__`` method The
    remaining arguments are the same as for the :class:`Request` class and are
    not documented here.
 
@@ -556,7 +556,7 @@ dealing with JSON requests.
 
    :param data: is any JSON serializable object that needs to be JSON encoded and assigned to body.
       if :attr:`Request.body` argument is provided this parameter will be ignored.
-      if :attr:`Request.body` argument is not provided and data argument is provided :attr:`Request.method` will be 
+      if :attr:`Request.body` argument is not provided and data argument is provided :attr:`Request.method` will be
       set to ``'POST'`` automatically.
    :type data: JSON serializable object
 
@@ -721,7 +721,7 @@ TextResponse objects
     :class:`Response` class, which is meant to be used only for binary data,
     such as images, sounds or any media file.
 
-    :class:`TextResponse` objects support a new constructor argument, in
+    :class:`TextResponse` objects support a new ``__init__`` method argument, in
     addition to the base :class:`Response` objects. The remaining functionality
     is the same as for the :class:`Response` class and is not documented here.
 
@@ -755,7 +755,7 @@ TextResponse objects
        A string with the encoding of this response. The encoding is resolved by
        trying the following mechanisms, in order:
 
-       1. the encoding passed in the constructor ``encoding`` argument
+       1. the encoding passed in the ``__init__`` method`` ``encoding`` argument
 
        2. the encoding declared in the Content-Type HTTP header. If this
           encoding is not valid (ie. unknown), it is ignored and the next

scrapy/exporters.py

@@ -31,7 +31,7 @@ def __init__(self, **kwargs):
     def _configure(self, options, dont_fail=False):
         """Configure the exporter by poping options from the ``options`` dict.
         If dont_fail is set, it won't raise an exception on unexpected options
-        (useful for using with keyword arguments in subclasses constructors)
+        (useful for using with keyword arguments in subclasses ``__init__`` methods)
         """
         self.encoding = options.pop('encoding', None)
         self.fields_to_export = options.pop('fields_to_export', None)

scrapy/extensions/feedexport.py

@@ -106,7 +106,7 @@ def __init__(self, uri, access_key=None, secret_key=None, acl=None):
                 warnings.warn(
                     "Initialising `scrapy.extensions.feedexport.S3FeedStorage` "
                     "without AWS keys is deprecated. Please supply credentials or "
-                    "use the `from_crawler()` constructor.",
+                    "use the `from_crawler()` ``__init__`` method.",
                     category=ScrapyDeprecationWarning,
                     stacklevel=2
                 )

scrapy/utils/datatypes.py

@@ -246,7 +246,7 @@ def pop(self, key, *args):
 class MergeDict(object):
     """
     A simple class for creating new "virtual" dictionaries that actually look
-    up values in more than one dictionary, passed in the constructor.
+    up values in more than one dictionary, passed in the ``__init__`` method.
 
     If a key appears in more than one of the given dictionaries, only the
     first occurrence will be used.