84 lines
2.2 KiB
Python
Executable File
84 lines
2.2 KiB
Python
Executable File
# Copyright 2008-2018 pydicom authors. See LICENSE file for details.
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"""Miscellaneous helper functions"""
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import logging
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from itertools import groupby
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from pathlib import Path
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import warnings
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LOGGER = logging.getLogger("pydicom")
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_size_factors = {
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"kb": 1000,
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"mb": 1000 * 1000,
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"gb": 1000 * 1000 * 1000,
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"kib": 1024,
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"mib": 1024 * 1024,
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"gib": 1024 * 1024 * 1024,
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}
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def size_in_bytes(expr: int | float | str | None) -> None | float | int:
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"""Return the number of bytes for `defer_size` argument in
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:func:`~pydicom.filereader.dcmread`.
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"""
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if expr is None or expr == float("inf"):
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return None
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if isinstance(expr, int | float):
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return expr
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try:
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return int(expr)
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except ValueError:
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pass
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value, unit = ("".join(g) for k, g in groupby(expr, str.isalpha))
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if unit.lower() in _size_factors:
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return float(value) * _size_factors[unit.lower()]
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raise ValueError(f"Unable to parse length with unit '{unit}'")
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def is_dicom(file_path: str | Path) -> bool:
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"""Return ``True`` if the file at `file_path` is a DICOM file.
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This function is a pared down version of
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:func:`~pydicom.filereader.read_preamble` meant for a fast return. The
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file is read for a conformant preamble ('DICM'), returning
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``True`` if so, and ``False`` otherwise. This is a conservative approach.
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Parameters
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----------
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file_path : str
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The path to the file.
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See Also
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--------
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filereader.read_preamble
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filereader.read_partial
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"""
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with open(file_path, "rb") as fp:
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fp.read(128) # preamble
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return fp.read(4) == b"DICM"
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def warn_and_log(
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msg: str, category: type[Warning] | None = None, stacklevel: int = 1
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) -> None:
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"""Send warning message `msg` to the logger.
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Parameters
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----------
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msg : str
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The warning message.
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category : type[Warning] | None, optional
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The warning category class, defaults to ``UserWarning``.
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stacklevel : int, optional
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The stack level to refer to, relative to where `warn_and_log` is used.
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"""
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LOGGER.warning(msg)
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warnings.warn(msg, category, stacklevel=stacklevel + 1)
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