from __future__ import annotations import binascii import codecs import os import typing from io import BytesIO from .fields import _TYPE_FIELD_VALUE_TUPLE, RequestField writer = codecs.lookup("utf-8")[3] _TYPE_FIELDS_SEQUENCE = typing.Sequence[ typing.Union[tuple[str, _TYPE_FIELD_VALUE_TUPLE], RequestField] ] _TYPE_FIELDS = typing.Union[ _TYPE_FIELDS_SEQUENCE, typing.Mapping[str, _TYPE_FIELD_VALUE_TUPLE], ] def choose_boundary() -> str: """ Our embarrassingly-simple replacement for mimetools.choose_boundary. """ return binascii.hexlify(os.urandom(16)).decode() def iter_field_objects(fields: _TYPE_FIELDS) -> typing.Iterable[RequestField]: """ Iterate over fields. Supports list of (k, v) tuples and dicts, and lists of :class:`~urllib3.fields.RequestField`. """ iterable: typing.Iterable[RequestField | tuple[str, _TYPE_FIELD_VALUE_TUPLE]] if isinstance(fields, typing.Mapping): iterable = fields.items() else: iterable = fields for field in iterable: if isinstance(field, RequestField): yield field else: yield RequestField.from_tuples(*field) def encode_multipart_formdata( fields: _TYPE_FIELDS, boundary: str | None = None ) -> tuple[bytes, str]: """ Encode a dictionary of ``fields`` using the multipart/form-data MIME format. :param fields: Dictionary of fields or list of (key, :class:`~urllib3.fields.RequestField`). Values are processed by :func:`urllib3.fields.RequestField.from_tuples`. :param boundary: If not specified, then a random boundary will be generated using :func:`urllib3.filepost.choose_boundary`. """ body = BytesIO() if boundary is None: boundary = choose_boundary() for field in iter_field_objects(fields): body.write(f"--{boundary}\r\n".encode("latin-1")) writer(body).write(field.render_headers()) data = field.data if isinstance(data, int): data = str(data) # Backwards compatibility if isinstance(data, str): writer(body).write(data) else: body.write(data) body.write(b"\r\n") body.write(f"--{boundary}--\r\n".encode("latin-1")) content_type = f"multipart/form-data; boundary={boundary}" return body.getvalue(), content_type