chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/graphviz/quoting.py

@@ -0,0 +1,221 @@
+"""Quote strings to be valid DOT identifiers, assemble quoted attribute lists."""
+
+import functools
+import re
+import typing
+import warnings
+
+from . import _tools
+from . import exceptions
+
+__all__ = ['quote', 'quote_edge',
+           'a_list', 'attr_list',
+           'escape', 'nohtml']
+
+# https://www.graphviz.org/doc/info/lang.html
+# https://www.graphviz.org/doc/info/attrs.html#k:escString
+
+HTML_STRING = re.compile(r'<.*>$', re.DOTALL)
+
+ID = re.compile(r'([a-zA-Z_][a-zA-Z0-9_]*|-?(\.[0-9]+|[0-9]+(\.[0-9]*)?))$')
+
+KEYWORDS = {'node', 'edge', 'graph', 'digraph', 'subgraph', 'strict'}
+
+COMPASS = {'n', 'ne', 'e', 'se', 's', 'sw', 'w', 'nw', 'c', '_'}  # TODO
+
+FINAL_ODD_BACKSLASHES = re.compile(r'(?<!\\)(?:\\{2})*\\$')
+
+QUOTE_WITH_OPTIONAL_BACKSLASHES = re.compile(r'''
+                                            (?P<escaped_backslashes>(?:\\{2})*)
+                                            \\?  # treat \" same as "
+                                            (?P<literal_quote>")
+                                            ''', flags=re.VERBOSE)
+
+ESCAPE_UNESCAPED_QUOTES = functools.partial(QUOTE_WITH_OPTIONAL_BACKSLASHES.sub,
+                                            r'\g<escaped_backslashes>'
+                                            r'\\'
+                                            r'\g<literal_quote>')
+
+
+@_tools.deprecate_positional_args(supported_number=1)
+def quote(identifier: str,
+          is_html_string=HTML_STRING.match,
+          is_valid_id=ID.match,
+          dot_keywords=KEYWORDS,
+          endswith_odd_number_of_backslashes=FINAL_ODD_BACKSLASHES.search,
+          escape_unescaped_quotes=ESCAPE_UNESCAPED_QUOTES) -> str:
+    r"""Return DOT identifier from string, quote if needed.
+
+    >>> quote('')  # doctest: +NO_EXE
+    '""'
+
+    >>> quote('spam')
+    'spam'
+
+    >>> quote('spam spam')
+    '"spam spam"'
+
+    >>> quote('-4.2')
+    '-4.2'
+
+    >>> quote('.42')
+    '.42'
+
+    >>> quote('<<b>spam</b>>')
+    '<<b>spam</b>>'
+
+    >>> quote(nohtml('<>'))
+    '"<>"'
+
+    >>> print(quote('"'))
+    "\""
+
+    >>> print(quote('\\"'))
+    "\""
+
+    >>> print(quote('\\\\"'))
+    "\\\""
+
+    >>> print(quote('\\\\\\"'))
+    "\\\""
+    """
+    if is_html_string(identifier) and not isinstance(identifier, NoHtml):
+        pass
+    elif not is_valid_id(identifier) or identifier.lower() in dot_keywords:
+        if endswith_odd_number_of_backslashes(identifier):
+            warnings.warn('expect syntax error scanning invalid quoted string:'
+                          f' {identifier!r}',
+                          category=exceptions.DotSyntaxWarning)
+        return f'"{escape_unescaped_quotes(identifier)}"'
+    return identifier
+
+
+def quote_edge(identifier: str) -> str:
+    """Return DOT edge statement node_id from string, quote if needed.
+
+    >>> quote_edge('spam')  # doctest: +NO_EXE
+    'spam'
+
+    >>> quote_edge('spam spam:eggs eggs')
+    '"spam spam":"eggs eggs"'
+
+    >>> quote_edge('spam:eggs:s')
+    'spam:eggs:s'
+    """
+    node, _, rest = identifier.partition(':')
+    parts = [quote(node)]
+    if rest:
+        port, _, compass = rest.partition(':')
+        parts.append(quote(port))
+        if compass:
+            parts.append(compass)
+    return ':'.join(parts)
+
+
+@_tools.deprecate_positional_args(supported_number=1)
+def a_list(label: typing.Optional[str] = None,
+           kwargs=None, attributes=None) -> str:
+    """Return assembled DOT a_list string.
+
+    >>> a_list('spam', kwargs={'spam': None, 'ham': 'ham ham', 'eggs': ''})  # doctest: +NO_EXE
+    'label=spam eggs="" ham="ham ham"'
+    """
+    result = [f'label={quote(label)}'] if label is not None else []
+    if kwargs:
+        result += [f'{quote(k)}={quote(v)}'
+                   for k, v in _tools.mapping_items(kwargs) if v is not None]
+    if attributes:
+        if hasattr(attributes, 'items'):
+            attributes = _tools.mapping_items(attributes)
+        result += [f'{quote(k)}={quote(v)}'
+                   for k, v in attributes if v is not None]
+    return ' '.join(result)
+
+
+@_tools.deprecate_positional_args(supported_number=1)
+def attr_list(label: typing.Optional[str] = None,
+              kwargs=None, attributes=None) -> str:
+    """Return assembled DOT attribute list string.
+
+    Sorts ``kwargs`` and ``attributes`` if they are plain dicts
+    (to avoid unpredictable order from hash randomization in Python < 3.7).
+
+    >>> attr_list()  # doctest: +NO_EXE
+    ''
+
+    >>> attr_list('spam spam', kwargs={'eggs': 'eggs', 'ham': 'ham ham'})
+    ' [label="spam spam" eggs=eggs ham="ham ham"]'
+
+    >>> attr_list(kwargs={'spam': None, 'eggs': ''})
+    ' [eggs=""]'
+    """
+    content = a_list(label, kwargs=kwargs, attributes=attributes)
+    if not content:
+        return ''
+    return f' [{content}]'
+
+
+class Quote:
+    """Quote strings to be valid DOT identifiers, assemble quoted attribute lists."""
+
+    _quote = staticmethod(quote)
+    _quote_edge = staticmethod(quote_edge)
+
+    _a_list = staticmethod(a_list)
+    _attr_list = staticmethod(attr_list)
+
+
+def escape(s: str) -> str:
+    r"""Return string disabling special meaning of backslashes and ``'<...>'``.
+
+    Args:
+        s: String in which backslashes and ``'<...>'``
+            should be treated as literal.
+
+    Returns:
+        Escaped string subclass instance.
+
+    Raises:
+        TypeError: If ``s`` is not a ``str``.
+
+    Example:
+        >>> import graphviz  # doctest: +NO_EXE
+        >>> print(graphviz.escape(r'\l'))
+        \\l
+
+    See also:
+        Upstream documentation:
+        https://www.graphviz.org/doc/info/attrs.html#k:escString
+    """
+    return nohtml(s.replace('\\', '\\\\'))
+
+
+class NoHtml(str):
+    """String subclass that does not treat ``'<...>'`` as DOT HTML string."""
+
+    __slots__ = ()
+
+
+def nohtml(s: str) -> str:
+    """Return string not treating ``'<...>'`` as DOT HTML string in quoting.
+
+    Args:
+        s: String in which leading ``'<'`` and trailing ``'>'``
+            should be treated as literal.
+
+    Returns:
+        String subclass instance.
+
+    Raises:
+        TypeError: If ``s`` is not a ``str``.
+
+    Example:
+        >>> import graphviz  # doctest: +NO_EXE
+        >>> g = graphviz.Graph()
+        >>> g.node(graphviz.nohtml('<>-*-<>'))
+        >>> print(g.source)  # doctest: +NORMALIZE_WHITESPACE
+        graph {
+            "<>-*-<>"
+        }
+    """
+    return NoHtml(s)