diff env/lib/python3.9/site-packages/jinja2/filters.py @ 0:4f3585e2f14b draft default tip

"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.9/site-packages/jinja2/filters.py	Mon Mar 22 18:12:50 2021 +0000
@@ -0,0 +1,1382 @@
+# -*- coding: utf-8 -*-
+"""Built-in template filters used with the ``|`` operator."""
+import math
+import random
+import re
+import warnings
+from collections import namedtuple
+from itertools import chain
+from itertools import groupby
+
+from markupsafe import escape
+from markupsafe import Markup
+from markupsafe import soft_unicode
+
+from ._compat import abc
+from ._compat import imap
+from ._compat import iteritems
+from ._compat import string_types
+from ._compat import text_type
+from .exceptions import FilterArgumentError
+from .runtime import Undefined
+from .utils import htmlsafe_json_dumps
+from .utils import pformat
+from .utils import unicode_urlencode
+from .utils import urlize
+
+_word_re = re.compile(r"\w+", re.UNICODE)
+_word_beginning_split_re = re.compile(r"([-\s\(\{\[\<]+)", re.UNICODE)
+
+
+def contextfilter(f):
+    """Decorator for marking context dependent filters. The current
+    :class:`Context` will be passed as first argument.
+    """
+    f.contextfilter = True
+    return f
+
+
+def evalcontextfilter(f):
+    """Decorator for marking eval-context dependent filters.  An eval
+    context object is passed as first argument.  For more information
+    about the eval context, see :ref:`eval-context`.
+
+    .. versionadded:: 2.4
+    """
+    f.evalcontextfilter = True
+    return f
+
+
+def environmentfilter(f):
+    """Decorator for marking environment dependent filters.  The current
+    :class:`Environment` is passed to the filter as first argument.
+    """
+    f.environmentfilter = True
+    return f
+
+
+def ignore_case(value):
+    """For use as a postprocessor for :func:`make_attrgetter`. Converts strings
+    to lowercase and returns other types as-is."""
+    return value.lower() if isinstance(value, string_types) else value
+
+
+def make_attrgetter(environment, attribute, postprocess=None, default=None):
+    """Returns a callable that looks up the given attribute from a
+    passed object with the rules of the environment.  Dots are allowed
+    to access attributes of attributes.  Integer parts in paths are
+    looked up as integers.
+    """
+    attribute = _prepare_attribute_parts(attribute)
+
+    def attrgetter(item):
+        for part in attribute:
+            item = environment.getitem(item, part)
+
+            if default and isinstance(item, Undefined):
+                item = default
+
+        if postprocess is not None:
+            item = postprocess(item)
+
+        return item
+
+    return attrgetter
+
+
+def make_multi_attrgetter(environment, attribute, postprocess=None):
+    """Returns a callable that looks up the given comma separated
+    attributes from a passed object with the rules of the environment.
+    Dots are allowed to access attributes of each attribute.  Integer
+    parts in paths are looked up as integers.
+
+    The value returned by the returned callable is a list of extracted
+    attribute values.
+
+    Examples of attribute: "attr1,attr2", "attr1.inner1.0,attr2.inner2.0", etc.
+    """
+    attribute_parts = (
+        attribute.split(",") if isinstance(attribute, string_types) else [attribute]
+    )
+    attribute = [
+        _prepare_attribute_parts(attribute_part) for attribute_part in attribute_parts
+    ]
+
+    def attrgetter(item):
+        items = [None] * len(attribute)
+        for i, attribute_part in enumerate(attribute):
+            item_i = item
+            for part in attribute_part:
+                item_i = environment.getitem(item_i, part)
+
+            if postprocess is not None:
+                item_i = postprocess(item_i)
+
+            items[i] = item_i
+        return items
+
+    return attrgetter
+
+
+def _prepare_attribute_parts(attr):
+    if attr is None:
+        return []
+    elif isinstance(attr, string_types):
+        return [int(x) if x.isdigit() else x for x in attr.split(".")]
+    else:
+        return [attr]
+
+
+def do_forceescape(value):
+    """Enforce HTML escaping.  This will probably double escape variables."""
+    if hasattr(value, "__html__"):
+        value = value.__html__()
+    return escape(text_type(value))
+
+
+def do_urlencode(value):
+    """Quote data for use in a URL path or query using UTF-8.
+
+    Basic wrapper around :func:`urllib.parse.quote` when given a
+    string, or :func:`urllib.parse.urlencode` for a dict or iterable.
+
+    :param value: Data to quote. A string will be quoted directly. A
+        dict or iterable of ``(key, value)`` pairs will be joined as a
+        query string.
+
+    When given a string, "/" is not quoted. HTTP servers treat "/" and
+    "%2F" equivalently in paths. If you need quoted slashes, use the
+    ``|replace("/", "%2F")`` filter.
+
+    .. versionadded:: 2.7
+    """
+    if isinstance(value, string_types) or not isinstance(value, abc.Iterable):
+        return unicode_urlencode(value)
+
+    if isinstance(value, dict):
+        items = iteritems(value)
+    else:
+        items = iter(value)
+
+    return u"&".join(
+        "%s=%s" % (unicode_urlencode(k, for_qs=True), unicode_urlencode(v, for_qs=True))
+        for k, v in items
+    )
+
+
+@evalcontextfilter
+def do_replace(eval_ctx, s, old, new, count=None):
+    """Return a copy of the value with all occurrences of a substring
+    replaced with a new one. The first argument is the substring
+    that should be replaced, the second is the replacement string.
+    If the optional third argument ``count`` is given, only the first
+    ``count`` occurrences are replaced:
+
+    .. sourcecode:: jinja
+
+        {{ "Hello World"|replace("Hello", "Goodbye") }}
+            -> Goodbye World
+
+        {{ "aaaaargh"|replace("a", "d'oh, ", 2) }}
+            -> d'oh, d'oh, aaargh
+    """
+    if count is None:
+        count = -1
+    if not eval_ctx.autoescape:
+        return text_type(s).replace(text_type(old), text_type(new), count)
+    if (
+        hasattr(old, "__html__")
+        or hasattr(new, "__html__")
+        and not hasattr(s, "__html__")
+    ):
+        s = escape(s)
+    else:
+        s = soft_unicode(s)
+    return s.replace(soft_unicode(old), soft_unicode(new), count)
+
+
+def do_upper(s):
+    """Convert a value to uppercase."""
+    return soft_unicode(s).upper()
+
+
+def do_lower(s):
+    """Convert a value to lowercase."""
+    return soft_unicode(s).lower()
+
+
+@evalcontextfilter
+def do_xmlattr(_eval_ctx, d, autospace=True):
+    """Create an SGML/XML attribute string based on the items in a dict.
+    All values that are neither `none` nor `undefined` are automatically
+    escaped:
+
+    .. sourcecode:: html+jinja
+
+        <ul{{ {'class': 'my_list', 'missing': none,
+                'id': 'list-%d'|format(variable)}|xmlattr }}>
+        ...
+        </ul>
+
+    Results in something like this:
+
+    .. sourcecode:: html
+
+        <ul class="my_list" id="list-42">
+        ...
+        </ul>
+
+    As you can see it automatically prepends a space in front of the item
+    if the filter returned something unless the second parameter is false.
+    """
+    rv = u" ".join(
+        u'%s="%s"' % (escape(key), escape(value))
+        for key, value in iteritems(d)
+        if value is not None and not isinstance(value, Undefined)
+    )
+    if autospace and rv:
+        rv = u" " + rv
+    if _eval_ctx.autoescape:
+        rv = Markup(rv)
+    return rv
+
+
+def do_capitalize(s):
+    """Capitalize a value. The first character will be uppercase, all others
+    lowercase.
+    """
+    return soft_unicode(s).capitalize()
+
+
+def do_title(s):
+    """Return a titlecased version of the value. I.e. words will start with
+    uppercase letters, all remaining characters are lowercase.
+    """
+    return "".join(
+        [
+            item[0].upper() + item[1:].lower()
+            for item in _word_beginning_split_re.split(soft_unicode(s))
+            if item
+        ]
+    )
+
+
+def do_dictsort(value, case_sensitive=False, by="key", reverse=False):
+    """Sort a dict and yield (key, value) pairs. Because python dicts are
+    unsorted you may want to use this function to order them by either
+    key or value:
+
+    .. sourcecode:: jinja
+
+        {% for key, value in mydict|dictsort %}
+            sort the dict by key, case insensitive
+
+        {% for key, value in mydict|dictsort(reverse=true) %}
+            sort the dict by key, case insensitive, reverse order
+
+        {% for key, value in mydict|dictsort(true) %}
+            sort the dict by key, case sensitive
+
+        {% for key, value in mydict|dictsort(false, 'value') %}
+            sort the dict by value, case insensitive
+    """
+    if by == "key":
+        pos = 0
+    elif by == "value":
+        pos = 1
+    else:
+        raise FilterArgumentError('You can only sort by either "key" or "value"')
+
+    def sort_func(item):
+        value = item[pos]
+
+        if not case_sensitive:
+            value = ignore_case(value)
+
+        return value
+
+    return sorted(value.items(), key=sort_func, reverse=reverse)
+
+
+@environmentfilter
+def do_sort(environment, value, reverse=False, case_sensitive=False, attribute=None):
+    """Sort an iterable using Python's :func:`sorted`.
+
+    .. sourcecode:: jinja
+
+        {% for city in cities|sort %}
+            ...
+        {% endfor %}
+
+    :param reverse: Sort descending instead of ascending.
+    :param case_sensitive: When sorting strings, sort upper and lower
+        case separately.
+    :param attribute: When sorting objects or dicts, an attribute or
+        key to sort by. Can use dot notation like ``"address.city"``.
+        Can be a list of attributes like ``"age,name"``.
+
+    The sort is stable, it does not change the relative order of
+    elements that compare equal. This makes it is possible to chain
+    sorts on different attributes and ordering.
+
+    .. sourcecode:: jinja
+
+        {% for user in users|sort(attribute="name")
+            |sort(reverse=true, attribute="age") %}
+            ...
+        {% endfor %}
+
+    As a shortcut to chaining when the direction is the same for all
+    attributes, pass a comma separate list of attributes.
+
+    .. sourcecode:: jinja
+
+        {% for user users|sort(attribute="age,name") %}
+            ...
+        {% endfor %}
+
+    .. versionchanged:: 2.11.0
+        The ``attribute`` parameter can be a comma separated list of
+        attributes, e.g. ``"age,name"``.
+
+    .. versionchanged:: 2.6
+       The ``attribute`` parameter was added.
+    """
+    key_func = make_multi_attrgetter(
+        environment, attribute, postprocess=ignore_case if not case_sensitive else None
+    )
+    return sorted(value, key=key_func, reverse=reverse)
+
+
+@environmentfilter
+def do_unique(environment, value, case_sensitive=False, attribute=None):
+    """Returns a list of unique items from the given iterable.
+
+    .. sourcecode:: jinja
+
+        {{ ['foo', 'bar', 'foobar', 'FooBar']|unique|list }}
+            -> ['foo', 'bar', 'foobar']
+
+    The unique items are yielded in the same order as their first occurrence in
+    the iterable passed to the filter.
+
+    :param case_sensitive: Treat upper and lower case strings as distinct.
+    :param attribute: Filter objects with unique values for this attribute.
+    """
+    getter = make_attrgetter(
+        environment, attribute, postprocess=ignore_case if not case_sensitive else None
+    )
+    seen = set()
+
+    for item in value:
+        key = getter(item)
+
+        if key not in seen:
+            seen.add(key)
+            yield item
+
+
+def _min_or_max(environment, value, func, case_sensitive, attribute):
+    it = iter(value)
+
+    try:
+        first = next(it)
+    except StopIteration:
+        return environment.undefined("No aggregated item, sequence was empty.")
+
+    key_func = make_attrgetter(
+        environment, attribute, postprocess=ignore_case if not case_sensitive else None
+    )
+    return func(chain([first], it), key=key_func)
+
+
+@environmentfilter
+def do_min(environment, value, case_sensitive=False, attribute=None):
+    """Return the smallest item from the sequence.
+
+    .. sourcecode:: jinja
+
+        {{ [1, 2, 3]|min }}
+            -> 1
+
+    :param case_sensitive: Treat upper and lower case strings as distinct.
+    :param attribute: Get the object with the min value of this attribute.
+    """
+    return _min_or_max(environment, value, min, case_sensitive, attribute)
+
+
+@environmentfilter
+def do_max(environment, value, case_sensitive=False, attribute=None):
+    """Return the largest item from the sequence.
+
+    .. sourcecode:: jinja
+
+        {{ [1, 2, 3]|max }}
+            -> 3
+
+    :param case_sensitive: Treat upper and lower case strings as distinct.
+    :param attribute: Get the object with the max value of this attribute.
+    """
+    return _min_or_max(environment, value, max, case_sensitive, attribute)
+
+
+def do_default(value, default_value=u"", boolean=False):
+    """If the value is undefined it will return the passed default value,
+    otherwise the value of the variable:
+
+    .. sourcecode:: jinja
+
+        {{ my_variable|default('my_variable is not defined') }}
+
+    This will output the value of ``my_variable`` if the variable was
+    defined, otherwise ``'my_variable is not defined'``. If you want
+    to use default with variables that evaluate to false you have to
+    set the second parameter to `true`:
+
+    .. sourcecode:: jinja
+
+        {{ ''|default('the string was empty', true) }}
+
+    .. versionchanged:: 2.11
+       It's now possible to configure the :class:`~jinja2.Environment` with
+       :class:`~jinja2.ChainableUndefined` to make the `default` filter work
+       on nested elements and attributes that may contain undefined values
+       in the chain without getting an :exc:`~jinja2.UndefinedError`.
+    """
+    if isinstance(value, Undefined) or (boolean and not value):
+        return default_value
+    return value
+
+
+@evalcontextfilter
+def do_join(eval_ctx, value, d=u"", attribute=None):
+    """Return a string which is the concatenation of the strings in the
+    sequence. The separator between elements is an empty string per
+    default, you can define it with the optional parameter:
+
+    .. sourcecode:: jinja
+
+        {{ [1, 2, 3]|join('|') }}
+            -> 1|2|3
+
+        {{ [1, 2, 3]|join }}
+            -> 123
+
+    It is also possible to join certain attributes of an object:
+
+    .. sourcecode:: jinja
+
+        {{ users|join(', ', attribute='username') }}
+
+    .. versionadded:: 2.6
+       The `attribute` parameter was added.
+    """
+    if attribute is not None:
+        value = imap(make_attrgetter(eval_ctx.environment, attribute), value)
+
+    # no automatic escaping?  joining is a lot easier then
+    if not eval_ctx.autoescape:
+        return text_type(d).join(imap(text_type, value))
+
+    # if the delimiter doesn't have an html representation we check
+    # if any of the items has.  If yes we do a coercion to Markup
+    if not hasattr(d, "__html__"):
+        value = list(value)
+        do_escape = False
+        for idx, item in enumerate(value):
+            if hasattr(item, "__html__"):
+                do_escape = True
+            else:
+                value[idx] = text_type(item)
+        if do_escape:
+            d = escape(d)
+        else:
+            d = text_type(d)
+        return d.join(value)
+
+    # no html involved, to normal joining
+    return soft_unicode(d).join(imap(soft_unicode, value))
+
+
+def do_center(value, width=80):
+    """Centers the value in a field of a given width."""
+    return text_type(value).center(width)
+
+
+@environmentfilter
+def do_first(environment, seq):
+    """Return the first item of a sequence."""
+    try:
+        return next(iter(seq))
+    except StopIteration:
+        return environment.undefined("No first item, sequence was empty.")
+
+
+@environmentfilter
+def do_last(environment, seq):
+    """
+    Return the last item of a sequence.
+
+    Note: Does not work with generators. You may want to explicitly
+    convert it to a list:
+
+    .. sourcecode:: jinja
+
+        {{ data | selectattr('name', '==', 'Jinja') | list | last }}
+    """
+    try:
+        return next(iter(reversed(seq)))
+    except StopIteration:
+        return environment.undefined("No last item, sequence was empty.")
+
+
+@contextfilter
+def do_random(context, seq):
+    """Return a random item from the sequence."""
+    try:
+        return random.choice(seq)
+    except IndexError:
+        return context.environment.undefined("No random item, sequence was empty.")
+
+
+def do_filesizeformat(value, binary=False):
+    """Format the value like a 'human-readable' file size (i.e. 13 kB,
+    4.1 MB, 102 Bytes, etc).  Per default decimal prefixes are used (Mega,
+    Giga, etc.), if the second parameter is set to `True` the binary
+    prefixes are used (Mebi, Gibi).
+    """
+    bytes = float(value)
+    base = binary and 1024 or 1000
+    prefixes = [
+        (binary and "KiB" or "kB"),
+        (binary and "MiB" or "MB"),
+        (binary and "GiB" or "GB"),
+        (binary and "TiB" or "TB"),
+        (binary and "PiB" or "PB"),
+        (binary and "EiB" or "EB"),
+        (binary and "ZiB" or "ZB"),
+        (binary and "YiB" or "YB"),
+    ]
+    if bytes == 1:
+        return "1 Byte"
+    elif bytes < base:
+        return "%d Bytes" % bytes
+    else:
+        for i, prefix in enumerate(prefixes):
+            unit = base ** (i + 2)
+            if bytes < unit:
+                return "%.1f %s" % ((base * bytes / unit), prefix)
+        return "%.1f %s" % ((base * bytes / unit), prefix)
+
+
+def do_pprint(value, verbose=False):
+    """Pretty print a variable. Useful for debugging.
+
+    With Jinja 1.2 onwards you can pass it a parameter.  If this parameter
+    is truthy the output will be more verbose (this requires `pretty`)
+    """
+    return pformat(value, verbose=verbose)
+
+
+@evalcontextfilter
+def do_urlize(
+    eval_ctx, value, trim_url_limit=None, nofollow=False, target=None, rel=None
+):
+    """Converts URLs in plain text into clickable links.
+
+    If you pass the filter an additional integer it will shorten the urls
+    to that number. Also a third argument exists that makes the urls
+    "nofollow":
+
+    .. sourcecode:: jinja
+
+        {{ mytext|urlize(40, true) }}
+            links are shortened to 40 chars and defined with rel="nofollow"
+
+    If *target* is specified, the ``target`` attribute will be added to the
+    ``<a>`` tag:
+
+    .. sourcecode:: jinja
+
+       {{ mytext|urlize(40, target='_blank') }}
+
+    .. versionchanged:: 2.8+
+       The *target* parameter was added.
+    """
+    policies = eval_ctx.environment.policies
+    rel = set((rel or "").split() or [])
+    if nofollow:
+        rel.add("nofollow")
+    rel.update((policies["urlize.rel"] or "").split())
+    if target is None:
+        target = policies["urlize.target"]
+    rel = " ".join(sorted(rel)) or None
+    rv = urlize(value, trim_url_limit, rel=rel, target=target)
+    if eval_ctx.autoescape:
+        rv = Markup(rv)
+    return rv
+
+
+def do_indent(s, width=4, first=False, blank=False, indentfirst=None):
+    """Return a copy of the string with each line indented by 4 spaces. The
+    first line and blank lines are not indented by default.
+
+    :param width: Number of spaces to indent by.
+    :param first: Don't skip indenting the first line.
+    :param blank: Don't skip indenting empty lines.
+
+    .. versionchanged:: 2.10
+        Blank lines are not indented by default.
+
+        Rename the ``indentfirst`` argument to ``first``.
+    """
+    if indentfirst is not None:
+        warnings.warn(
+            "The 'indentfirst' argument is renamed to 'first' and will"
+            " be removed in version 3.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        first = indentfirst
+
+    indention = u" " * width
+    newline = u"\n"
+
+    if isinstance(s, Markup):
+        indention = Markup(indention)
+        newline = Markup(newline)
+
+    s += newline  # this quirk is necessary for splitlines method
+
+    if blank:
+        rv = (newline + indention).join(s.splitlines())
+    else:
+        lines = s.splitlines()
+        rv = lines.pop(0)
+
+        if lines:
+            rv += newline + newline.join(
+                indention + line if line else line for line in lines
+            )
+
+    if first:
+        rv = indention + rv
+
+    return rv
+
+
+@environmentfilter
+def do_truncate(env, s, length=255, killwords=False, end="...", leeway=None):
+    """Return a truncated copy of the string. The length is specified
+    with the first parameter which defaults to ``255``. If the second
+    parameter is ``true`` the filter will cut the text at length. Otherwise
+    it will discard the last word. If the text was in fact
+    truncated it will append an ellipsis sign (``"..."``). If you want a
+    different ellipsis sign than ``"..."`` you can specify it using the
+    third parameter. Strings that only exceed the length by the tolerance
+    margin given in the fourth parameter will not be truncated.
+
+    .. sourcecode:: jinja
+
+        {{ "foo bar baz qux"|truncate(9) }}
+            -> "foo..."
+        {{ "foo bar baz qux"|truncate(9, True) }}
+            -> "foo ba..."
+        {{ "foo bar baz qux"|truncate(11) }}
+            -> "foo bar baz qux"
+        {{ "foo bar baz qux"|truncate(11, False, '...', 0) }}
+            -> "foo bar..."
+
+    The default leeway on newer Jinja versions is 5 and was 0 before but
+    can be reconfigured globally.
+    """
+    if leeway is None:
+        leeway = env.policies["truncate.leeway"]
+    assert length >= len(end), "expected length >= %s, got %s" % (len(end), length)
+    assert leeway >= 0, "expected leeway >= 0, got %s" % leeway
+    if len(s) <= length + leeway:
+        return s
+    if killwords:
+        return s[: length - len(end)] + end
+    result = s[: length - len(end)].rsplit(" ", 1)[0]
+    return result + end
+
+
+@environmentfilter
+def do_wordwrap(
+    environment,
+    s,
+    width=79,
+    break_long_words=True,
+    wrapstring=None,
+    break_on_hyphens=True,
+):
+    """Wrap a string to the given width. Existing newlines are treated
+    as paragraphs to be wrapped separately.
+
+    :param s: Original text to wrap.
+    :param width: Maximum length of wrapped lines.
+    :param break_long_words: If a word is longer than ``width``, break
+        it across lines.
+    :param break_on_hyphens: If a word contains hyphens, it may be split
+        across lines.
+    :param wrapstring: String to join each wrapped line. Defaults to
+        :attr:`Environment.newline_sequence`.
+
+    .. versionchanged:: 2.11
+        Existing newlines are treated as paragraphs wrapped separately.
+
+    .. versionchanged:: 2.11
+        Added the ``break_on_hyphens`` parameter.
+
+    .. versionchanged:: 2.7
+        Added the ``wrapstring`` parameter.
+    """
+
+    import textwrap
+
+    if not wrapstring:
+        wrapstring = environment.newline_sequence
+
+    # textwrap.wrap doesn't consider existing newlines when wrapping.
+    # If the string has a newline before width, wrap will still insert
+    # a newline at width, resulting in a short line. Instead, split and
+    # wrap each paragraph individually.
+    return wrapstring.join(
+        [
+            wrapstring.join(
+                textwrap.wrap(
+                    line,
+                    width=width,
+                    expand_tabs=False,
+                    replace_whitespace=False,
+                    break_long_words=break_long_words,
+                    break_on_hyphens=break_on_hyphens,
+                )
+            )
+            for line in s.splitlines()
+        ]
+    )
+
+
+def do_wordcount(s):
+    """Count the words in that string."""
+    return len(_word_re.findall(soft_unicode(s)))
+
+
+def do_int(value, default=0, base=10):
+    """Convert the value into an integer. If the
+    conversion doesn't work it will return ``0``. You can
+    override this default using the first parameter. You
+    can also override the default base (10) in the second
+    parameter, which handles input with prefixes such as
+    0b, 0o and 0x for bases 2, 8 and 16 respectively.
+    The base is ignored for decimal numbers and non-string values.
+    """
+    try:
+        if isinstance(value, string_types):
+            return int(value, base)
+        return int(value)
+    except (TypeError, ValueError):
+        # this quirk is necessary so that "42.23"|int gives 42.
+        try:
+            return int(float(value))
+        except (TypeError, ValueError):
+            return default
+
+
+def do_float(value, default=0.0):
+    """Convert the value into a floating point number. If the
+    conversion doesn't work it will return ``0.0``. You can
+    override this default using the first parameter.
+    """
+    try:
+        return float(value)
+    except (TypeError, ValueError):
+        return default
+
+
+def do_format(value, *args, **kwargs):
+    """Apply the given values to a `printf-style`_ format string, like
+    ``string % values``.
+
+    .. sourcecode:: jinja
+
+        {{ "%s, %s!"|format(greeting, name) }}
+        Hello, World!
+
+    In most cases it should be more convenient and efficient to use the
+    ``%`` operator or :meth:`str.format`.
+
+    .. code-block:: text
+
+        {{ "%s, %s!" % (greeting, name) }}
+        {{ "{}, {}!".format(greeting, name) }}
+
+    .. _printf-style: https://docs.python.org/library/stdtypes.html
+        #printf-style-string-formatting
+    """
+    if args and kwargs:
+        raise FilterArgumentError(
+            "can't handle positional and keyword arguments at the same time"
+        )
+    return soft_unicode(value) % (kwargs or args)
+
+
+def do_trim(value, chars=None):
+    """Strip leading and trailing characters, by default whitespace."""
+    return soft_unicode(value).strip(chars)
+
+
+def do_striptags(value):
+    """Strip SGML/XML tags and replace adjacent whitespace by one space."""
+    if hasattr(value, "__html__"):
+        value = value.__html__()
+    return Markup(text_type(value)).striptags()
+
+
+def do_slice(value, slices, fill_with=None):
+    """Slice an iterator and return a list of lists containing
+    those items. Useful if you want to create a div containing
+    three ul tags that represent columns:
+
+    .. sourcecode:: html+jinja
+
+        <div class="columnwrapper">
+          {%- for column in items|slice(3) %}
+            <ul class="column-{{ loop.index }}">
+            {%- for item in column %}
+              <li>{{ item }}</li>
+            {%- endfor %}
+            </ul>
+          {%- endfor %}
+        </div>
+
+    If you pass it a second argument it's used to fill missing
+    values on the last iteration.
+    """
+    seq = list(value)
+    length = len(seq)
+    items_per_slice = length // slices
+    slices_with_extra = length % slices
+    offset = 0
+    for slice_number in range(slices):
+        start = offset + slice_number * items_per_slice
+        if slice_number < slices_with_extra:
+            offset += 1
+        end = offset + (slice_number + 1) * items_per_slice
+        tmp = seq[start:end]
+        if fill_with is not None and slice_number >= slices_with_extra:
+            tmp.append(fill_with)
+        yield tmp
+
+
+def do_batch(value, linecount, fill_with=None):
+    """
+    A filter that batches items. It works pretty much like `slice`
+    just the other way round. It returns a list of lists with the
+    given number of items. If you provide a second parameter this
+    is used to fill up missing items. See this example:
+
+    .. sourcecode:: html+jinja
+
+        <table>
+        {%- for row in items|batch(3, '&nbsp;') %}
+          <tr>
+          {%- for column in row %}
+            <td>{{ column }}</td>
+          {%- endfor %}
+          </tr>
+        {%- endfor %}
+        </table>
+    """
+    tmp = []
+    for item in value:
+        if len(tmp) == linecount:
+            yield tmp
+            tmp = []
+        tmp.append(item)
+    if tmp:
+        if fill_with is not None and len(tmp) < linecount:
+            tmp += [fill_with] * (linecount - len(tmp))
+        yield tmp
+
+
+def do_round(value, precision=0, method="common"):
+    """Round the number to a given precision. The first
+    parameter specifies the precision (default is ``0``), the
+    second the rounding method:
+
+    - ``'common'`` rounds either up or down
+    - ``'ceil'`` always rounds up
+    - ``'floor'`` always rounds down
+
+    If you don't specify a method ``'common'`` is used.
+
+    .. sourcecode:: jinja
+
+        {{ 42.55|round }}
+            -> 43.0
+        {{ 42.55|round(1, 'floor') }}
+            -> 42.5
+
+    Note that even if rounded to 0 precision, a float is returned.  If
+    you need a real integer, pipe it through `int`:
+
+    .. sourcecode:: jinja
+
+        {{ 42.55|round|int }}
+            -> 43
+    """
+    if method not in {"common", "ceil", "floor"}:
+        raise FilterArgumentError("method must be common, ceil or floor")
+    if method == "common":
+        return round(value, precision)
+    func = getattr(math, method)
+    return func(value * (10 ** precision)) / (10 ** precision)
+
+
+# Use a regular tuple repr here.  This is what we did in the past and we
+# really want to hide this custom type as much as possible.  In particular
+# we do not want to accidentally expose an auto generated repr in case
+# people start to print this out in comments or something similar for
+# debugging.
+_GroupTuple = namedtuple("_GroupTuple", ["grouper", "list"])
+_GroupTuple.__repr__ = tuple.__repr__
+_GroupTuple.__str__ = tuple.__str__
+
+
+@environmentfilter
+def do_groupby(environment, value, attribute):
+    """Group a sequence of objects by an attribute using Python's
+    :func:`itertools.groupby`. The attribute can use dot notation for
+    nested access, like ``"address.city"``. Unlike Python's ``groupby``,
+    the values are sorted first so only one group is returned for each
+    unique value.
+
+    For example, a list of ``User`` objects with a ``city`` attribute
+    can be rendered in groups. In this example, ``grouper`` refers to
+    the ``city`` value of the group.
+
+    .. sourcecode:: html+jinja
+
+        <ul>{% for city, items in users|groupby("city") %}
+          <li>{{ city }}
+            <ul>{% for user in items %}
+              <li>{{ user.name }}
+            {% endfor %}</ul>
+          </li>
+        {% endfor %}</ul>
+
+    ``groupby`` yields namedtuples of ``(grouper, list)``, which
+    can be used instead of the tuple unpacking above. ``grouper`` is the
+    value of the attribute, and ``list`` is the items with that value.
+
+    .. sourcecode:: html+jinja
+
+        <ul>{% for group in users|groupby("city") %}
+          <li>{{ group.grouper }}: {{ group.list|join(", ") }}
+        {% endfor %}</ul>
+
+    .. versionchanged:: 2.6
+        The attribute supports dot notation for nested access.
+    """
+    expr = make_attrgetter(environment, attribute)
+    return [
+        _GroupTuple(key, list(values))
+        for key, values in groupby(sorted(value, key=expr), expr)
+    ]
+
+
+@environmentfilter
+def do_sum(environment, iterable, attribute=None, start=0):
+    """Returns the sum of a sequence of numbers plus the value of parameter
+    'start' (which defaults to 0).  When the sequence is empty it returns
+    start.
+
+    It is also possible to sum up only certain attributes:
+
+    .. sourcecode:: jinja
+
+        Total: {{ items|sum(attribute='price') }}
+
+    .. versionchanged:: 2.6
+       The `attribute` parameter was added to allow suming up over
+       attributes.  Also the `start` parameter was moved on to the right.
+    """
+    if attribute is not None:
+        iterable = imap(make_attrgetter(environment, attribute), iterable)
+    return sum(iterable, start)
+
+
+def do_list(value):
+    """Convert the value into a list.  If it was a string the returned list
+    will be a list of characters.
+    """
+    return list(value)
+
+
+def do_mark_safe(value):
+    """Mark the value as safe which means that in an environment with automatic
+    escaping enabled this variable will not be escaped.
+    """
+    return Markup(value)
+
+
+def do_mark_unsafe(value):
+    """Mark a value as unsafe.  This is the reverse operation for :func:`safe`."""
+    return text_type(value)
+
+
+def do_reverse(value):
+    """Reverse the object or return an iterator that iterates over it the other
+    way round.
+    """
+    if isinstance(value, string_types):
+        return value[::-1]
+    try:
+        return reversed(value)
+    except TypeError:
+        try:
+            rv = list(value)
+            rv.reverse()
+            return rv
+        except TypeError:
+            raise FilterArgumentError("argument must be iterable")
+
+
+@environmentfilter
+def do_attr(environment, obj, name):
+    """Get an attribute of an object.  ``foo|attr("bar")`` works like
+    ``foo.bar`` just that always an attribute is returned and items are not
+    looked up.
+
+    See :ref:`Notes on subscriptions <notes-on-subscriptions>` for more details.
+    """
+    try:
+        name = str(name)
+    except UnicodeError:
+        pass
+    else:
+        try:
+            value = getattr(obj, name)
+        except AttributeError:
+            pass
+        else:
+            if environment.sandboxed and not environment.is_safe_attribute(
+                obj, name, value
+            ):
+                return environment.unsafe_undefined(obj, name)
+            return value
+    return environment.undefined(obj=obj, name=name)
+
+
+@contextfilter
+def do_map(*args, **kwargs):
+    """Applies a filter on a sequence of objects or looks up an attribute.
+    This is useful when dealing with lists of objects but you are really
+    only interested in a certain value of it.
+
+    The basic usage is mapping on an attribute.  Imagine you have a list
+    of users but you are only interested in a list of usernames:
+
+    .. sourcecode:: jinja
+
+        Users on this page: {{ users|map(attribute='username')|join(', ') }}
+
+    You can specify a ``default`` value to use if an object in the list
+    does not have the given attribute.
+
+    .. sourcecode:: jinja
+
+        {{ users|map(attribute="username", default="Anonymous")|join(", ") }}
+
+    Alternatively you can let it invoke a filter by passing the name of the
+    filter and the arguments afterwards.  A good example would be applying a
+    text conversion filter on a sequence:
+
+    .. sourcecode:: jinja
+
+        Users on this page: {{ titles|map('lower')|join(', ') }}
+
+    Similar to a generator comprehension such as:
+
+    .. code-block:: python
+
+        (u.username for u in users)
+        (u.username or "Anonymous" for u in users)
+        (do_lower(x) for x in titles)
+
+    .. versionchanged:: 2.11.0
+        Added the ``default`` parameter.
+
+    .. versionadded:: 2.7
+    """
+    seq, func = prepare_map(args, kwargs)
+    if seq:
+        for item in seq:
+            yield func(item)
+
+
+@contextfilter
+def do_select(*args, **kwargs):
+    """Filters a sequence of objects by applying a test to each object,
+    and only selecting the objects with the test succeeding.
+
+    If no test is specified, each object will be evaluated as a boolean.
+
+    Example usage:
+
+    .. sourcecode:: jinja
+
+        {{ numbers|select("odd") }}
+        {{ numbers|select("odd") }}
+        {{ numbers|select("divisibleby", 3) }}
+        {{ numbers|select("lessthan", 42) }}
+        {{ strings|select("equalto", "mystring") }}
+
+    Similar to a generator comprehension such as:
+
+    .. code-block:: python
+
+        (n for n in numbers if test_odd(n))
+        (n for n in numbers if test_divisibleby(n, 3))
+
+    .. versionadded:: 2.7
+    """
+    return select_or_reject(args, kwargs, lambda x: x, False)
+
+
+@contextfilter
+def do_reject(*args, **kwargs):
+    """Filters a sequence of objects by applying a test to each object,
+    and rejecting the objects with the test succeeding.
+
+    If no test is specified, each object will be evaluated as a boolean.
+
+    Example usage:
+
+    .. sourcecode:: jinja
+
+        {{ numbers|reject("odd") }}
+
+    Similar to a generator comprehension such as:
+
+    .. code-block:: python
+
+        (n for n in numbers if not test_odd(n))
+
+    .. versionadded:: 2.7
+    """
+    return select_or_reject(args, kwargs, lambda x: not x, False)
+
+
+@contextfilter
+def do_selectattr(*args, **kwargs):
+    """Filters a sequence of objects by applying a test to the specified
+    attribute of each object, and only selecting the objects with the
+    test succeeding.
+
+    If no test is specified, the attribute's value will be evaluated as
+    a boolean.
+
+    Example usage:
+
+    .. sourcecode:: jinja
+
+        {{ users|selectattr("is_active") }}
+        {{ users|selectattr("email", "none") }}
+
+    Similar to a generator comprehension such as:
+
+    .. code-block:: python
+
+        (u for user in users if user.is_active)
+        (u for user in users if test_none(user.email))
+
+    .. versionadded:: 2.7
+    """
+    return select_or_reject(args, kwargs, lambda x: x, True)
+
+
+@contextfilter
+def do_rejectattr(*args, **kwargs):
+    """Filters a sequence of objects by applying a test to the specified
+    attribute of each object, and rejecting the objects with the test
+    succeeding.
+
+    If no test is specified, the attribute's value will be evaluated as
+    a boolean.
+
+    .. sourcecode:: jinja
+
+        {{ users|rejectattr("is_active") }}
+        {{ users|rejectattr("email", "none") }}
+
+    Similar to a generator comprehension such as:
+
+    .. code-block:: python
+
+        (u for user in users if not user.is_active)
+        (u for user in users if not test_none(user.email))
+
+    .. versionadded:: 2.7
+    """
+    return select_or_reject(args, kwargs, lambda x: not x, True)
+
+
+@evalcontextfilter
+def do_tojson(eval_ctx, value, indent=None):
+    """Dumps a structure to JSON so that it's safe to use in ``<script>``
+    tags.  It accepts the same arguments and returns a JSON string.  Note that
+    this is available in templates through the ``|tojson`` filter which will
+    also mark the result as safe.  Due to how this function escapes certain
+    characters this is safe even if used outside of ``<script>`` tags.
+
+    The following characters are escaped in strings:
+
+    -   ``<``
+    -   ``>``
+    -   ``&``
+    -   ``'``
+
+    This makes it safe to embed such strings in any place in HTML with the
+    notable exception of double quoted attributes.  In that case single
+    quote your attributes or HTML escape it in addition.
+
+    The indent parameter can be used to enable pretty printing.  Set it to
+    the number of spaces that the structures should be indented with.
+
+    Note that this filter is for use in HTML contexts only.
+
+    .. versionadded:: 2.9
+    """
+    policies = eval_ctx.environment.policies
+    dumper = policies["json.dumps_function"]
+    options = policies["json.dumps_kwargs"]
+    if indent is not None:
+        options = dict(options)
+        options["indent"] = indent
+    return htmlsafe_json_dumps(value, dumper=dumper, **options)
+
+
+def prepare_map(args, kwargs):
+    context = args[0]
+    seq = args[1]
+    default = None
+
+    if len(args) == 2 and "attribute" in kwargs:
+        attribute = kwargs.pop("attribute")
+        default = kwargs.pop("default", None)
+        if kwargs:
+            raise FilterArgumentError(
+                "Unexpected keyword argument %r" % next(iter(kwargs))
+            )
+        func = make_attrgetter(context.environment, attribute, default=default)
+    else:
+        try:
+            name = args[2]
+            args = args[3:]
+        except LookupError:
+            raise FilterArgumentError("map requires a filter argument")
+
+        def func(item):
+            return context.environment.call_filter(
+                name, item, args, kwargs, context=context
+            )
+
+    return seq, func
+
+
+def prepare_select_or_reject(args, kwargs, modfunc, lookup_attr):
+    context = args[0]
+    seq = args[1]
+    if lookup_attr:
+        try:
+            attr = args[2]
+        except LookupError:
+            raise FilterArgumentError("Missing parameter for attribute name")
+        transfunc = make_attrgetter(context.environment, attr)
+        off = 1
+    else:
+        off = 0
+
+        def transfunc(x):
+            return x
+
+    try:
+        name = args[2 + off]
+        args = args[3 + off :]
+
+        def func(item):
+            return context.environment.call_test(name, item, args, kwargs)
+
+    except LookupError:
+        func = bool
+
+    return seq, lambda item: modfunc(func(transfunc(item)))
+
+
+def select_or_reject(args, kwargs, modfunc, lookup_attr):
+    seq, func = prepare_select_or_reject(args, kwargs, modfunc, lookup_attr)
+    if seq:
+        for item in seq:
+            if func(item):
+                yield item
+
+
+FILTERS = {
+    "abs": abs,
+    "attr": do_attr,
+    "batch": do_batch,
+    "capitalize": do_capitalize,
+    "center": do_center,
+    "count": len,
+    "d": do_default,
+    "default": do_default,
+    "dictsort": do_dictsort,
+    "e": escape,
+    "escape": escape,
+    "filesizeformat": do_filesizeformat,
+    "first": do_first,
+    "float": do_float,
+    "forceescape": do_forceescape,
+    "format": do_format,
+    "groupby": do_groupby,
+    "indent": do_indent,
+    "int": do_int,
+    "join": do_join,
+    "last": do_last,
+    "length": len,
+    "list": do_list,
+    "lower": do_lower,
+    "map": do_map,
+    "min": do_min,
+    "max": do_max,
+    "pprint": do_pprint,
+    "random": do_random,
+    "reject": do_reject,
+    "rejectattr": do_rejectattr,
+    "replace": do_replace,
+    "reverse": do_reverse,
+    "round": do_round,
+    "safe": do_mark_safe,
+    "select": do_select,
+    "selectattr": do_selectattr,
+    "slice": do_slice,
+    "sort": do_sort,
+    "string": soft_unicode,
+    "striptags": do_striptags,
+    "sum": do_sum,
+    "title": do_title,
+    "trim": do_trim,
+    "truncate": do_truncate,
+    "unique": do_unique,
+    "upper": do_upper,
+    "urlencode": do_urlencode,
+    "urlize": do_urlize,
+    "wordcount": do_wordcount,
+    "wordwrap": do_wordwrap,
+    "xmlattr": do_xmlattr,
+    "tojson": do_tojson,
+}