修改为东南天坐标系

backend_service/venv/lib/python3.13/site-packages/oxmsg/attachment.py

@@ -0,0 +1,80 @@
+"""Provides access to the properties of an attachment in an Outlook MSG file.
+
+These properies include the attached file's original file-name, its last-modified date, size, and
+content-type (MIME-type).
+
+```python
+>>> from oxmsg import Message
+
+>>> msg = Message.load("message.msg")
+>>> msg.attachment_count
+1
+>>> attachment = msg.attachments[0]
+>>> attachment.file_name
+'financial-forecast.xlsx'
+>>> with open(attachment.file_name, "wb") as f:
+...     f.write()
+```
+"""
+
+from __future__ import annotations
+
+import datetime as dt
+
+from oxmsg.domain import constants as c
+from oxmsg.domain import model as m
+from oxmsg.properties import Properties
+from oxmsg.util import lazyproperty
+
+
+class Attachment:
+    """A file attached to an Outlook email message."""
+
+    def __init__(self, storage: m.StorageT):
+        self._storage = storage
+
+    @lazyproperty
+    def attached_by_value(self) -> bool:
+        """True when the `PidTagAttachDataBinary` property contains the attachment data.
+
+        This is as opposed to "by-reference" where only a path or URL is stored.
+        """
+        attach_method = self.properties.int_prop_value(c.PID_ATTACH_METHOD)
+        assert attach_method is not None
+        return bool(attach_method & m.AF_BY_VALUE)
+
+    @lazyproperty
+    def file_bytes(self) -> bytes | None:
+        """The attachment binary, suitable for saving to a file when detaching."""
+        return self.properties.binary_prop_value(c.PID_ATTACH_DATA_BINARY)
+
+    @lazyproperty
+    def file_name(self) -> str | None:
+        """The full name of this file as it was originally attached.
+
+        Like "FY24-quarterly-projections.xlsx". Does not include a path.
+        """
+        return self.properties.str_prop_value(c.PID_ATTACH_LONG_FILENAME)
+
+    @lazyproperty
+    def last_modified(self) -> dt.datetime | None:
+        """Timezone-aware UTC datetime when this attachment was last modified.
+
+        `None` if this property is not present on the attachment.
+        """
+        return self.properties.date_prop_value(c.PID_LAST_MODIFICATION_TIME)
+
+    @lazyproperty
+    def mime_type(self) -> str | None:
+        """ISO 8601 str representation of time this attachment was last modified."""
+        return self.properties.str_prop_value(c.PID_ATTACH_MIME_TAG) or "application/octet-stream"
+
+    @lazyproperty
+    def properties(self) -> Properties:
+        """Provides access to the properties of this OXMSG object."""
+        return Properties(self._storage, properties_header_offset=m.ATTACH_HDR_OFFSET)
+
+    @lazyproperty
+    def size(self) -> int:
+        """Length in bytes of this attachment."""
+        return len(self.file_bytes) if self.file_bytes else 0