CK ZhangandGitHub
11d60a7487
* compat: support Python 3.13 (imghdr removal) * compat: drop unnecessary future annotations import
52 lines
1.4 KiB
Python
52 lines
1.4 KiB
Python
import io
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from pathlib import Path
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from PIL import Image
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try:
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import imghdr as _imghdr
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except ModuleNotFoundError: # Python 3.13+
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_imghdr = None
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def what(file: str | Path | None = None, h: bytes | None = None) -> str | None:
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"""
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Compatibility wrapper for the removed stdlib `imghdr` module (Python 3.13+).
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Behaves like `imghdr.what(file, h)` and returns a lowercase format string
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like "jpeg", "png", "gif", or None if unknown.
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"""
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if _imghdr is not None:
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return _imghdr.what(file, h)
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if h is not None:
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return _what_from_bytes(h)
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if file is None:
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return None
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try:
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with Image.open(str(file)) as im:
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fmt = im.format
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except Exception:
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return None
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return fmt.lower() if fmt else None
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def _what_from_bytes(data: bytes) -> str | None:
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if data.startswith(b"\xff\xd8\xff"):
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return "jpeg"
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if data.startswith(b"\x89PNG\r\n\x1a\n"):
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return "png"
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if data[:6] in (b"GIF87a", b"GIF89a"):
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return "gif"
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if data.startswith(b"BM"):
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return "bmp"
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if len(data) >= 12 and data.startswith(b"RIFF") and data[8:12] == b"WEBP":
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return "webp"
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if data.startswith(b"II*\x00") or data.startswith(b"MM\x00*"):
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return "tiff"
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try:
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with Image.open(io.BytesIO(data)) as im:
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fmt = im.format
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except Exception:
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return None
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return fmt.lower() if fmt else None
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