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Reference for ultralytics/utils/checks.py

Note

This file is available at https://github.com/ultralytics/ultralytics/blob/main/ultralytics/utils/checks.py. If you spot a problem please help fix it by contributing a Pull Request 🛠️. Thank you 🙏!



ultralytics.utils.checks.parse_requirements(file_path=ROOT.parent / 'requirements.txt', package='')

Parse a requirements.txt file, ignoring lines that start with '#' and any text after '#'.

Parameters:

Name Type Description Default
file_path Path

Path to the requirements.txt file.

parent / 'requirements.txt'
package str

Python package to use instead of requirements.txt file, i.e. package='ultralytics'.

''

Returns:

Type Description
List[Dict[str, str]]

List of parsed requirements as dictionaries with name and specifier keys.

Example
from ultralytics.utils.checks import parse_requirements

parse_requirements(package='ultralytics')
Source code in ultralytics/utils/checks.py
def parse_requirements(file_path=ROOT.parent / "requirements.txt", package=""):
    """
    Parse a requirements.txt file, ignoring lines that start with '#' and any text after '#'.

    Args:
        file_path (Path): Path to the requirements.txt file.
        package (str, optional): Python package to use instead of requirements.txt file, i.e. package='ultralytics'.

    Returns:
        (List[Dict[str, str]]): List of parsed requirements as dictionaries with `name` and `specifier` keys.

    Example:
        ```python
        from ultralytics.utils.checks import parse_requirements

        parse_requirements(package='ultralytics')
        ```
    """

    if package:
        requires = [x for x in metadata.distribution(package).requires if "extra == " not in x]
    else:
        requires = Path(file_path).read_text().splitlines()

    requirements = []
    for line in requires:
        line = line.strip()
        if line and not line.startswith("#"):
            line = line.split("#")[0].strip()  # ignore inline comments
            match = re.match(r"([a-zA-Z0-9-_]+)\s*([<>!=~]+.*)?", line)
            if match:
                requirements.append(SimpleNamespace(name=match[1], specifier=match[2].strip() if match[2] else ""))

    return requirements



ultralytics.utils.checks.parse_version(version='0.0.0')

Convert a version string to a tuple of integers, ignoring any extra non-numeric string attached to the version. This function replaces deprecated 'pkg_resources.parse_version(v)'.

Parameters:

Name Type Description Default
version str

Version string, i.e. '2.0.1+cpu'

'0.0.0'

Returns:

Type Description
tuple

Tuple of integers representing the numeric part of the version and the extra string, i.e. (2, 0, 1)

Source code in ultralytics/utils/checks.py
def parse_version(version="0.0.0") -> tuple:
    """
    Convert a version string to a tuple of integers, ignoring any extra non-numeric string attached to the version. This
    function replaces deprecated 'pkg_resources.parse_version(v)'.

    Args:
        version (str): Version string, i.e. '2.0.1+cpu'

    Returns:
        (tuple): Tuple of integers representing the numeric part of the version and the extra string, i.e. (2, 0, 1)
    """
    try:
        return tuple(map(int, re.findall(r"\d+", version)[:3]))  # '2.0.1+cpu' -> (2, 0, 1)
    except Exception as e:
        LOGGER.warning(f"WARNING ⚠️ failure for parse_version({version}), returning (0, 0, 0): {e}")
        return 0, 0, 0



ultralytics.utils.checks.is_ascii(s)

Check if a string is composed of only ASCII characters.

Parameters:

Name Type Description Default
s str

String to be checked.

required

Returns:

Type Description
bool

True if the string is composed only of ASCII characters, False otherwise.

Source code in ultralytics/utils/checks.py
def is_ascii(s) -> bool:
    """
    Check if a string is composed of only ASCII characters.

    Args:
        s (str): String to be checked.

    Returns:
        (bool): True if the string is composed only of ASCII characters, False otherwise.
    """
    # Convert list, tuple, None, etc. to string
    s = str(s)

    # Check if the string is composed of only ASCII characters
    return all(ord(c) < 128 for c in s)



ultralytics.utils.checks.check_imgsz(imgsz, stride=32, min_dim=1, max_dim=2, floor=0)

Verify image size is a multiple of the given stride in each dimension. If the image size is not a multiple of the stride, update it to the nearest multiple of the stride that is greater than or equal to the given floor value.

Parameters:

Name Type Description Default
imgsz int | cList[int]

Image size.

required
stride int

Stride value.

32
min_dim int

Minimum number of dimensions.

1
max_dim int

Maximum number of dimensions.

2
floor int

Minimum allowed value for image size.

0

Returns:

Type Description
List[int]

Updated image size.

Source code in ultralytics/utils/checks.py
def check_imgsz(imgsz, stride=32, min_dim=1, max_dim=2, floor=0):
    """
    Verify image size is a multiple of the given stride in each dimension. If the image size is not a multiple of the
    stride, update it to the nearest multiple of the stride that is greater than or equal to the given floor value.

    Args:
        imgsz (int | cList[int]): Image size.
        stride (int): Stride value.
        min_dim (int): Minimum number of dimensions.
        max_dim (int): Maximum number of dimensions.
        floor (int): Minimum allowed value for image size.

    Returns:
        (List[int]): Updated image size.
    """
    # Convert stride to integer if it is a tensor
    stride = int(stride.max() if isinstance(stride, torch.Tensor) else stride)

    # Convert image size to list if it is an integer
    if isinstance(imgsz, int):
        imgsz = [imgsz]
    elif isinstance(imgsz, (list, tuple)):
        imgsz = list(imgsz)
    elif isinstance(imgsz, str):  # i.e. '640' or '[640,640]'
        imgsz = [int(imgsz)] if imgsz.isnumeric() else eval(imgsz)
    else:
        raise TypeError(
            f"'imgsz={imgsz}' is of invalid type {type(imgsz).__name__}. "
            f"Valid imgsz types are int i.e. 'imgsz=640' or list i.e. 'imgsz=[640,640]'"
        )

    # Apply max_dim
    if len(imgsz) > max_dim:
        msg = (
            "'train' and 'val' imgsz must be an integer, while 'predict' and 'export' imgsz may be a [h, w] list "
            "or an integer, i.e. 'yolo export imgsz=640,480' or 'yolo export imgsz=640'"
        )
        if max_dim != 1:
            raise ValueError(f"imgsz={imgsz} is not a valid image size. {msg}")
        LOGGER.warning(f"WARNING ⚠️ updating to 'imgsz={max(imgsz)}'. {msg}")
        imgsz = [max(imgsz)]
    # Make image size a multiple of the stride
    sz = [max(math.ceil(x / stride) * stride, floor) for x in imgsz]

    # Print warning message if image size was updated
    if sz != imgsz:
        LOGGER.warning(f"WARNING ⚠️ imgsz={imgsz} must be multiple of max stride {stride}, updating to {sz}")

    # Add missing dimensions if necessary
    sz = [sz[0], sz[0]] if min_dim == 2 and len(sz) == 1 else sz[0] if min_dim == 1 and len(sz) == 1 else sz

    return sz



ultralytics.utils.checks.check_version(current='0.0.0', required='0.0.0', name='version', hard=False, verbose=False, msg='')

Check current version against the required version or range.

Parameters:

Name Type Description Default
current str

Current version or package name to get version from.

'0.0.0'
required str

Required version or range (in pip-style format).

'0.0.0'
name str

Name to be used in warning message.

'version'
hard bool

If True, raise an AssertionError if the requirement is not met.

False
verbose bool

If True, print warning message if requirement is not met.

False
msg str

Extra message to display if verbose.

''

Returns:

Type Description
bool

True if requirement is met, False otherwise.

Example
# Check if current version is exactly 22.04
check_version(current='22.04', required='==22.04')

# Check if current version is greater than or equal to 22.04
check_version(current='22.10', required='22.04')  # assumes '>=' inequality if none passed

# Check if current version is less than or equal to 22.04
check_version(current='22.04', required='<=22.04')

# Check if current version is between 20.04 (inclusive) and 22.04 (exclusive)
check_version(current='21.10', required='>20.04,<22.04')
Source code in ultralytics/utils/checks.py
def check_version(
    current: str = "0.0.0",
    required: str = "0.0.0",
    name: str = "version",
    hard: bool = False,
    verbose: bool = False,
    msg: str = "",
) -> bool:
    """
    Check current version against the required version or range.

    Args:
        current (str): Current version or package name to get version from.
        required (str): Required version or range (in pip-style format).
        name (str, optional): Name to be used in warning message.
        hard (bool, optional): If True, raise an AssertionError if the requirement is not met.
        verbose (bool, optional): If True, print warning message if requirement is not met.
        msg (str, optional): Extra message to display if verbose.

    Returns:
        (bool): True if requirement is met, False otherwise.

    Example:
        ```python
        # Check if current version is exactly 22.04
        check_version(current='22.04', required='==22.04')

        # Check if current version is greater than or equal to 22.04
        check_version(current='22.10', required='22.04')  # assumes '>=' inequality if none passed

        # Check if current version is less than or equal to 22.04
        check_version(current='22.04', required='<=22.04')

        # Check if current version is between 20.04 (inclusive) and 22.04 (exclusive)
        check_version(current='21.10', required='>20.04,<22.04')
        ```
    """
    if not current:  # if current is '' or None
        LOGGER.warning(f"WARNING ⚠️ invalid check_version({current}, {required}) requested, please check values.")
        return True
    elif not current[0].isdigit():  # current is package name rather than version string, i.e. current='ultralytics'
        try:
            name = current  # assigned package name to 'name' arg
            current = metadata.version(current)  # get version string from package name
        except metadata.PackageNotFoundError as e:
            if hard:
                raise ModuleNotFoundError(emojis(f"WARNING ⚠️ {current} package is required but not installed")) from e
            else:
                return False

    if not required:  # if required is '' or None
        return True

    op = ""
    version = ""
    result = True
    c = parse_version(current)  # '1.2.3' -> (1, 2, 3)
    for r in required.strip(",").split(","):
        op, version = re.match(r"([^0-9]*)([\d.]+)", r).groups()  # split '>=22.04' -> ('>=', '22.04')
        v = parse_version(version)  # '1.2.3' -> (1, 2, 3)
        if op == "==" and c != v:
            result = False
        elif op == "!=" and c == v:
            result = False
        elif op in {">=", ""} and not (c >= v):  # if no constraint passed assume '>=required'
            result = False
        elif op == "<=" and not (c <= v):
            result = False
        elif op == ">" and not (c > v):
            result = False
        elif op == "<" and not (c < v):
            result = False
    if not result:
        warning = f"WARNING ⚠️ {name}{op}{version} is required, but {name}=={current} is currently installed {msg}"
        if hard:
            raise ModuleNotFoundError(emojis(warning))  # assert version requirements met
        if verbose:
            LOGGER.warning(warning)
    return result



ultralytics.utils.checks.check_latest_pypi_version(package_name='ultralytics')

Returns the latest version of a PyPI package without downloading or installing it.

Parameters:

Name Type Description Default
package_name str

The name of the package to find the latest version for.

'ultralytics'

Returns:

Type Description
str

The latest version of the package.

Source code in ultralytics/utils/checks.py
def check_latest_pypi_version(package_name="ultralytics"):
    """
    Returns the latest version of a PyPI package without downloading or installing it.

    Parameters:
        package_name (str): The name of the package to find the latest version for.

    Returns:
        (str): The latest version of the package.
    """
    with contextlib.suppress(Exception):
        requests.packages.urllib3.disable_warnings()  # Disable the InsecureRequestWarning
        response = requests.get(f"https://pypi.org/pypi/{package_name}/json", timeout=3)
        if response.status_code == 200:
            return response.json()["info"]["version"]



ultralytics.utils.checks.check_pip_update_available()

Checks if a new version of the ultralytics package is available on PyPI.

Returns:

Type Description
bool

True if an update is available, False otherwise.

Source code in ultralytics/utils/checks.py
def check_pip_update_available():
    """
    Checks if a new version of the ultralytics package is available on PyPI.

    Returns:
        (bool): True if an update is available, False otherwise.
    """
    if ONLINE and IS_PIP_PACKAGE:
        with contextlib.suppress(Exception):
            from ultralytics import __version__

            latest = check_latest_pypi_version()
            if check_version(__version__, f"<{latest}"):  # check if current version is < latest version
                LOGGER.info(
                    f"New https://pypi.org/project/ultralytics/{latest} available 😃 "
                    f"Update with 'pip install -U ultralytics'"
                )
                return True
    return False



ultralytics.utils.checks.check_font(font='Arial.ttf')

Find font locally or download to user's configuration directory if it does not already exist.

Parameters:

Name Type Description Default
font str

Path or name of font.

'Arial.ttf'

Returns:

Name Type Description
file Path

Resolved font file path.

Source code in ultralytics/utils/checks.py
@ThreadingLocked()
def check_font(font="Arial.ttf"):
    """
    Find font locally or download to user's configuration directory if it does not already exist.

    Args:
        font (str): Path or name of font.

    Returns:
        file (Path): Resolved font file path.
    """
    from matplotlib import font_manager

    # Check USER_CONFIG_DIR
    name = Path(font).name
    file = USER_CONFIG_DIR / name
    if file.exists():
        return file

    # Check system fonts
    matches = [s for s in font_manager.findSystemFonts() if font in s]
    if any(matches):
        return matches[0]

    # Download to USER_CONFIG_DIR if missing
    url = f"https://ultralytics.com/assets/{name}"
    if downloads.is_url(url, check=True):
        downloads.safe_download(url=url, file=file)
        return file



ultralytics.utils.checks.check_python(minimum='3.8.0', hard=True)

Check current python version against the required minimum version.

Parameters:

Name Type Description Default
minimum str

Required minimum version of python.

'3.8.0'
hard bool

If True, raise an AssertionError if the requirement is not met.

True

Returns:

Type Description
bool

Whether the installed Python version meets the minimum constraints.

Source code in ultralytics/utils/checks.py
def check_python(minimum: str = "3.8.0", hard: bool = True) -> bool:
    """
    Check current python version against the required minimum version.

    Args:
        minimum (str): Required minimum version of python.
        hard (bool, optional): If True, raise an AssertionError if the requirement is not met.

    Returns:
        (bool): Whether the installed Python version meets the minimum constraints.
    """
    return check_version(PYTHON_VERSION, minimum, name="Python", hard=hard)



ultralytics.utils.checks.check_requirements(requirements=ROOT.parent / 'requirements.txt', exclude=(), install=True, cmds='')

Check if installed dependencies meet YOLOv8 requirements and attempt to auto-update if needed.

Parameters:

Name Type Description Default
requirements Union[Path, str, List[str]]

Path to a requirements.txt file, a single package requirement as a string, or a list of package requirements as strings.

parent / 'requirements.txt'
exclude Tuple[str]

Tuple of package names to exclude from checking.

()
install bool

If True, attempt to auto-update packages that don't meet requirements.

True
cmds str

Additional commands to pass to the pip install command when auto-updating.

''
Example
from ultralytics.utils.checks import check_requirements

# Check a requirements.txt file
check_requirements('path/to/requirements.txt')

# Check a single package
check_requirements('ultralytics>=8.0.0')

# Check multiple packages
check_requirements(['numpy', 'ultralytics>=8.0.0'])
Source code in ultralytics/utils/checks.py
@TryExcept()
def check_requirements(requirements=ROOT.parent / "requirements.txt", exclude=(), install=True, cmds=""):
    """
    Check if installed dependencies meet YOLOv8 requirements and attempt to auto-update if needed.

    Args:
        requirements (Union[Path, str, List[str]]): Path to a requirements.txt file, a single package requirement as a
            string, or a list of package requirements as strings.
        exclude (Tuple[str]): Tuple of package names to exclude from checking.
        install (bool): If True, attempt to auto-update packages that don't meet requirements.
        cmds (str): Additional commands to pass to the pip install command when auto-updating.

    Example:
        ```python
        from ultralytics.utils.checks import check_requirements

        # Check a requirements.txt file
        check_requirements('path/to/requirements.txt')

        # Check a single package
        check_requirements('ultralytics>=8.0.0')

        # Check multiple packages
        check_requirements(['numpy', 'ultralytics>=8.0.0'])
        ```
    """

    prefix = colorstr("red", "bold", "requirements:")
    check_python()  # check python version
    check_torchvision()  # check torch-torchvision compatibility
    if isinstance(requirements, Path):  # requirements.txt file
        file = requirements.resolve()
        assert file.exists(), f"{prefix} {file} not found, check failed."
        requirements = [f"{x.name}{x.specifier}" for x in parse_requirements(file) if x.name not in exclude]
    elif isinstance(requirements, str):
        requirements = [requirements]

    pkgs = []
    for r in requirements:
        r_stripped = r.split("/")[-1].replace(".git", "")  # replace git+https://org/repo.git -> 'repo'
        match = re.match(r"([a-zA-Z0-9-_]+)([<>!=~]+.*)?", r_stripped)
        name, required = match[1], match[2].strip() if match[2] else ""
        try:
            assert check_version(metadata.version(name), required)  # exception if requirements not met
        except (AssertionError, metadata.PackageNotFoundError):
            pkgs.append(r)

    @Retry(times=2, delay=1)
    def attempt_install(packages, commands):
        """Attempt pip install command with retries on failure."""
        return subprocess.check_output(f"pip install --no-cache-dir {packages} {commands}", shell=True).decode()

    s = " ".join(f'"{x}"' for x in pkgs)  # console string
    if s:
        if install and AUTOINSTALL:  # check environment variable
            n = len(pkgs)  # number of packages updates
            LOGGER.info(f"{prefix} Ultralytics requirement{'s' * (n > 1)} {pkgs} not found, attempting AutoUpdate...")
            try:
                t = time.time()
                assert ONLINE, "AutoUpdate skipped (offline)"
                LOGGER.info(attempt_install(s, cmds))
                dt = time.time() - t
                LOGGER.info(
                    f"{prefix} AutoUpdate success ✅ {dt:.1f}s, installed {n} package{'s' * (n > 1)}: {pkgs}\n"
                    f"{prefix} ⚠️ {colorstr('bold', 'Restart runtime or rerun command for updates to take effect')}\n"
                )
            except Exception as e:
                LOGGER.warning(f"{prefix}{e}")
                return False
        else:
            return False

    return True



ultralytics.utils.checks.check_torchvision()

Checks the installed versions of PyTorch and Torchvision to ensure they're compatible.

This function checks the installed versions of PyTorch and Torchvision, and warns if they're incompatible according to the provided compatibility table based on: https://github.com/pytorch/vision#installation.

The compatibility table is a dictionary where the keys are PyTorch versions and the values are lists of compatible Torchvision versions.

Source code in ultralytics/utils/checks.py
def check_torchvision():
    """
    Checks the installed versions of PyTorch and Torchvision to ensure they're compatible.

    This function checks the installed versions of PyTorch and Torchvision, and warns if they're incompatible according
    to the provided compatibility table based on:
    https://github.com/pytorch/vision#installation.

    The compatibility table is a dictionary where the keys are PyTorch versions and the values are lists of compatible
    Torchvision versions.
    """

    # Compatibility table
    compatibility_table = {
        "2.3": ["0.18"],
        "2.2": ["0.17"],
        "2.1": ["0.16"],
        "2.0": ["0.15"],
        "1.13": ["0.14"],
        "1.12": ["0.13"],
    }

    # Extract only the major and minor versions
    v_torch = ".".join(torch.__version__.split("+")[0].split(".")[:2])
    if v_torch in compatibility_table:
        compatible_versions = compatibility_table[v_torch]
        v_torchvision = ".".join(TORCHVISION_VERSION.split("+")[0].split(".")[:2])
        if all(v_torchvision != v for v in compatible_versions):
            print(
                f"WARNING ⚠️ torchvision=={v_torchvision} is incompatible with torch=={v_torch}.\n"
                f"Run 'pip install torchvision=={compatible_versions[0]}' to fix torchvision or "
                "'pip install -U torch torchvision' to update both.\n"
                "For a full compatibility table see https://github.com/pytorch/vision#installation"
            )



ultralytics.utils.checks.check_suffix(file='yolov8n.pt', suffix='.pt', msg='')

Check file(s) for acceptable suffix.

Source code in ultralytics/utils/checks.py
def check_suffix(file="yolov8n.pt", suffix=".pt", msg=""):
    """Check file(s) for acceptable suffix."""
    if file and suffix:
        if isinstance(suffix, str):
            suffix = (suffix,)
        for f in file if isinstance(file, (list, tuple)) else [file]:
            s = Path(f).suffix.lower().strip()  # file suffix
            if len(s):
                assert s in suffix, f"{msg}{f} acceptable suffix is {suffix}, not {s}"



ultralytics.utils.checks.check_yolov5u_filename(file, verbose=True)

Replace legacy YOLOv5 filenames with updated YOLOv5u filenames.

Source code in ultralytics/utils/checks.py
def check_yolov5u_filename(file: str, verbose: bool = True):
    """Replace legacy YOLOv5 filenames with updated YOLOv5u filenames."""
    if "yolov3" in file or "yolov5" in file:
        if "u.yaml" in file:
            file = file.replace("u.yaml", ".yaml")  # i.e. yolov5nu.yaml -> yolov5n.yaml
        elif ".pt" in file and "u" not in file:
            original_file = file
            file = re.sub(r"(.*yolov5([nsmlx]))\.pt", "\\1u.pt", file)  # i.e. yolov5n.pt -> yolov5nu.pt
            file = re.sub(r"(.*yolov5([nsmlx])6)\.pt", "\\1u.pt", file)  # i.e. yolov5n6.pt -> yolov5n6u.pt
            file = re.sub(r"(.*yolov3(|-tiny|-spp))\.pt", "\\1u.pt", file)  # i.e. yolov3-spp.pt -> yolov3-sppu.pt
            if file != original_file and verbose:
                LOGGER.info(
                    f"PRO TIP 💡 Replace 'model={original_file}' with new 'model={file}'.\nYOLOv5 'u' models are "
                    f"trained with https://github.com/ultralytics/ultralytics and feature improved performance vs "
                    f"standard YOLOv5 models trained with https://github.com/ultralytics/yolov5.\n"
                )
    return file



ultralytics.utils.checks.check_model_file_from_stem(model='yolov8n')

Return a model filename from a valid model stem.

Source code in ultralytics/utils/checks.py
def check_model_file_from_stem(model="yolov8n"):
    """Return a model filename from a valid model stem."""
    if model and not Path(model).suffix and Path(model).stem in downloads.GITHUB_ASSETS_STEMS:
        return Path(model).with_suffix(".pt")  # add suffix, i.e. yolov8n -> yolov8n.pt
    else:
        return model



ultralytics.utils.checks.check_file(file, suffix='', download=True, hard=True)

Search/download file (if necessary) and return path.

Source code in ultralytics/utils/checks.py
def check_file(file, suffix="", download=True, hard=True):
    """Search/download file (if necessary) and return path."""
    check_suffix(file, suffix)  # optional
    file = str(file).strip()  # convert to string and strip spaces
    file = check_yolov5u_filename(file)  # yolov5n -> yolov5nu
    if (
        not file
        or ("://" not in file and Path(file).exists())  # '://' check required in Windows Python<3.10
        or file.lower().startswith("grpc://")
    ):  # file exists or gRPC Triton images
        return file
    elif download and file.lower().startswith(("https://", "http://", "rtsp://", "rtmp://", "tcp://")):  # download
        url = file  # warning: Pathlib turns :// -> :/
        file = url2file(file)  # '%2F' to '/', split https://url.com/file.txt?auth
        if Path(file).exists():
            LOGGER.info(f"Found {clean_url(url)} locally at {file}")  # file already exists
        else:
            downloads.safe_download(url=url, file=file, unzip=False)
        return file
    else:  # search
        files = glob.glob(str(ROOT / "**" / file), recursive=True) or glob.glob(str(ROOT.parent / file))  # find file
        if not files and hard:
            raise FileNotFoundError(f"'{file}' does not exist")
        elif len(files) > 1 and hard:
            raise FileNotFoundError(f"Multiple files match '{file}', specify exact path: {files}")
        return files[0] if len(files) else []  # return file



ultralytics.utils.checks.check_yaml(file, suffix=('.yaml', '.yml'), hard=True)

Search/download YAML file (if necessary) and return path, checking suffix.

Source code in ultralytics/utils/checks.py
def check_yaml(file, suffix=(".yaml", ".yml"), hard=True):
    """Search/download YAML file (if necessary) and return path, checking suffix."""
    return check_file(file, suffix, hard=hard)



ultralytics.utils.checks.check_is_path_safe(basedir, path)

Check if the resolved path is under the intended directory to prevent path traversal.

Parameters:

Name Type Description Default
basedir Path | str

The intended directory.

required
path Path | str

The path to check.

required

Returns:

Type Description
bool

True if the path is safe, False otherwise.

Source code in ultralytics/utils/checks.py
def check_is_path_safe(basedir, path):
    """
    Check if the resolved path is under the intended directory to prevent path traversal.

    Args:
        basedir (Path | str): The intended directory.
        path (Path | str): The path to check.

    Returns:
        (bool): True if the path is safe, False otherwise.
    """
    base_dir_resolved = Path(basedir).resolve()
    path_resolved = Path(path).resolve()

    return path_resolved.exists() and path_resolved.parts[: len(base_dir_resolved.parts)] == base_dir_resolved.parts



ultralytics.utils.checks.check_imshow(warn=False)

Check if environment supports image displays.

Source code in ultralytics/utils/checks.py
def check_imshow(warn=False):
    """Check if environment supports image displays."""
    try:
        if LINUX:
            assert not IS_COLAB and not IS_KAGGLE
            assert "DISPLAY" in os.environ, "The DISPLAY environment variable isn't set."
        cv2.imshow("test", np.zeros((8, 8, 3), dtype=np.uint8))  # show a small 8-pixel image
        cv2.waitKey(1)
        cv2.destroyAllWindows()
        cv2.waitKey(1)
        return True
    except Exception as e:
        if warn:
            LOGGER.warning(f"WARNING ⚠️ Environment does not support cv2.imshow() or PIL Image.show()\n{e}")
        return False



ultralytics.utils.checks.check_yolo(verbose=True, device='')

Return a human-readable YOLO software and hardware summary.

Source code in ultralytics/utils/checks.py
def check_yolo(verbose=True, device=""):
    """Return a human-readable YOLO software and hardware summary."""
    import psutil

    from ultralytics.utils.torch_utils import select_device

    if IS_JUPYTER:
        if check_requirements("wandb", install=False):
            os.system("pip uninstall -y wandb")  # uninstall wandb: unwanted account creation prompt with infinite hang
        if IS_COLAB:
            shutil.rmtree("sample_data", ignore_errors=True)  # remove colab /sample_data directory

    if verbose:
        # System info
        gib = 1 << 30  # bytes per GiB
        ram = psutil.virtual_memory().total
        total, used, free = shutil.disk_usage("/")
        s = f"({os.cpu_count()} CPUs, {ram / gib:.1f} GB RAM, {(total - free) / gib:.1f}/{total / gib:.1f} GB disk)"
        with contextlib.suppress(Exception):  # clear display if ipython is installed
            from IPython import display

            display.clear_output()
    else:
        s = ""

    select_device(device=device, newline=False)
    LOGGER.info(f"Setup complete ✅ {s}")



ultralytics.utils.checks.collect_system_info()

Collect and print relevant system information including OS, Python, RAM, CPU, and CUDA.

Source code in ultralytics/utils/checks.py
def collect_system_info():
    """Collect and print relevant system information including OS, Python, RAM, CPU, and CUDA."""

    import psutil

    from ultralytics.utils import ENVIRONMENT, IS_GIT_DIR
    from ultralytics.utils.torch_utils import get_cpu_info

    ram_info = psutil.virtual_memory().total / (1024**3)  # Convert bytes to GB
    check_yolo()
    LOGGER.info(
        f"\n{'OS':<20}{platform.platform()}\n"
        f"{'Environment':<20}{ENVIRONMENT}\n"
        f"{'Python':<20}{PYTHON_VERSION}\n"
        f"{'Install':<20}{'git' if IS_GIT_DIR else 'pip' if IS_PIP_PACKAGE else 'other'}\n"
        f"{'RAM':<20}{ram_info:.2f} GB\n"
        f"{'CPU':<20}{get_cpu_info()}\n"
        f"{'CUDA':<20}{torch.version.cuda if torch and torch.cuda.is_available() else None}\n"
    )

    for r in parse_requirements(package="ultralytics"):
        try:
            current = metadata.version(r.name)
            is_met = "✅ " if check_version(current, str(r.specifier), hard=True) else "❌ "
        except metadata.PackageNotFoundError:
            current = "(not installed)"
            is_met = "❌ "
        LOGGER.info(f"{r.name:<20}{is_met}{current}{r.specifier}")

    if is_github_action_running():
        LOGGER.info(
            f"\nRUNNER_OS: {os.getenv('RUNNER_OS')}\n"
            f"GITHUB_EVENT_NAME: {os.getenv('GITHUB_EVENT_NAME')}\n"
            f"GITHUB_WORKFLOW: {os.getenv('GITHUB_WORKFLOW')}\n"
            f"GITHUB_ACTOR: {os.getenv('GITHUB_ACTOR')}\n"
            f"GITHUB_REPOSITORY: {os.getenv('GITHUB_REPOSITORY')}\n"
            f"GITHUB_REPOSITORY_OWNER: {os.getenv('GITHUB_REPOSITORY_OWNER')}\n"
        )



ultralytics.utils.checks.check_amp(model)

This function checks the PyTorch Automatic Mixed Precision (AMP) functionality of a YOLOv8 model. If the checks fail, it means there are anomalies with AMP on the system that may cause NaN losses or zero-mAP results, so AMP will be disabled during training.

Parameters:

Name Type Description Default
model Module

A YOLOv8 model instance.

required
Example
from ultralytics import YOLO
from ultralytics.utils.checks import check_amp

model = YOLO('yolov8n.pt').model.cuda()
check_amp(model)

Returns:

Type Description
bool

Returns True if the AMP functionality works correctly with YOLOv8 model, else False.

Source code in ultralytics/utils/checks.py
def check_amp(model):
    """
    This function checks the PyTorch Automatic Mixed Precision (AMP) functionality of a YOLOv8 model. If the checks
    fail, it means there are anomalies with AMP on the system that may cause NaN losses or zero-mAP results, so AMP will
    be disabled during training.

    Args:
        model (nn.Module): A YOLOv8 model instance.

    Example:
        ```python
        from ultralytics import YOLO
        from ultralytics.utils.checks import check_amp

        model = YOLO('yolov8n.pt').model.cuda()
        check_amp(model)
        ```

    Returns:
        (bool): Returns True if the AMP functionality works correctly with YOLOv8 model, else False.
    """
    device = next(model.parameters()).device  # get model device
    if device.type in {"cpu", "mps"}:
        return False  # AMP only used on CUDA devices

    def amp_allclose(m, im):
        """All close FP32 vs AMP results."""
        a = m(im, device=device, verbose=False)[0].boxes.data  # FP32 inference
        with torch.cuda.amp.autocast(True):
            b = m(im, device=device, verbose=False)[0].boxes.data  # AMP inference
        del m
        return a.shape == b.shape and torch.allclose(a, b.float(), atol=0.5)  # close to 0.5 absolute tolerance

    im = ASSETS / "bus.jpg"  # image to check
    prefix = colorstr("AMP: ")
    LOGGER.info(f"{prefix}running Automatic Mixed Precision (AMP) checks with YOLOv8n...")
    warning_msg = "Setting 'amp=True'. If you experience zero-mAP or NaN losses you can disable AMP with amp=False."
    try:
        from ultralytics import YOLO

        assert amp_allclose(YOLO("yolov8n.pt"), im)
        LOGGER.info(f"{prefix}checks passed ✅")
    except ConnectionError:
        LOGGER.warning(f"{prefix}checks skipped ⚠️, offline and unable to download YOLOv8n. {warning_msg}")
    except (AttributeError, ModuleNotFoundError):
        LOGGER.warning(
            f"{prefix}checks skipped ⚠️. "
            f"Unable to load YOLOv8n due to possible Ultralytics package modifications. {warning_msg}"
        )
    except AssertionError:
        LOGGER.warning(
            f"{prefix}checks failed ❌. Anomalies were detected with AMP on your system that may lead to "
            f"NaN losses or zero-mAP results, so AMP will be disabled during training."
        )
        return False
    return True



ultralytics.utils.checks.git_describe(path=ROOT)

Return human-readable git description, i.e. v5.0-5-g3e25f1e https://git-scm.com/docs/git-describe.

Source code in ultralytics/utils/checks.py
def git_describe(path=ROOT):  # path must be a directory
    """Return human-readable git description, i.e. v5.0-5-g3e25f1e https://git-scm.com/docs/git-describe."""
    with contextlib.suppress(Exception):
        return subprocess.check_output(f"git -C {path} describe --tags --long --always", shell=True).decode()[:-1]
    return ""



ultralytics.utils.checks.print_args(args=None, show_file=True, show_func=False)

Print function arguments (optional args dict).

Source code in ultralytics/utils/checks.py
def print_args(args: Optional[dict] = None, show_file=True, show_func=False):
    """Print function arguments (optional args dict)."""

    def strip_auth(v):
        """Clean longer Ultralytics HUB URLs by stripping potential authentication information."""
        return clean_url(v) if (isinstance(v, str) and v.startswith("http") and len(v) > 100) else v

    x = inspect.currentframe().f_back  # previous frame
    file, _, func, _, _ = inspect.getframeinfo(x)
    if args is None:  # get args automatically
        args, _, _, frm = inspect.getargvalues(x)
        args = {k: v for k, v in frm.items() if k in args}
    try:
        file = Path(file).resolve().relative_to(ROOT).with_suffix("")
    except ValueError:
        file = Path(file).stem
    s = (f"{file}: " if show_file else "") + (f"{func}: " if show_func else "")
    LOGGER.info(colorstr(s) + ", ".join(f"{k}={strip_auth(v)}" for k, v in args.items()))



ultralytics.utils.checks.cuda_device_count()

Get the number of NVIDIA GPUs available in the environment.

Returns:

Type Description
int

The number of NVIDIA GPUs available.

Source code in ultralytics/utils/checks.py
def cuda_device_count() -> int:
    """
    Get the number of NVIDIA GPUs available in the environment.

    Returns:
        (int): The number of NVIDIA GPUs available.
    """
    try:
        # Run the nvidia-smi command and capture its output
        output = subprocess.check_output(
            ["nvidia-smi", "--query-gpu=count", "--format=csv,noheader,nounits"], encoding="utf-8"
        )

        # Take the first line and strip any leading/trailing white space
        first_line = output.strip().split("\n")[0]

        return int(first_line)
    except (subprocess.CalledProcessError, FileNotFoundError, ValueError):
        # If the command fails, nvidia-smi is not found, or output is not an integer, assume no GPUs are available
        return 0



ultralytics.utils.checks.cuda_is_available()

Check if CUDA is available in the environment.

Returns:

Type Description
bool

True if one or more NVIDIA GPUs are available, False otherwise.

Source code in ultralytics/utils/checks.py
def cuda_is_available() -> bool:
    """
    Check if CUDA is available in the environment.

    Returns:
        (bool): True if one or more NVIDIA GPUs are available, False otherwise.
    """
    return cuda_device_count() > 0





Created 2023-11-12, Updated 2024-06-02
Authors: glenn-jocher (5), Burhan-Q (1), Laughing-q (1)