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prefect.utilities.hashing

file_hash

Given a path to a file, produces a stable hash of the file contents.

Parameters:

Name Description Default
path

the path to a file

str
required

Returns:

Type Description
str

a hash of the file contents

Source code in prefect/utilities/hashing.py
def file_hash(path: str) -> str:
    """Given a path to a file, produces a stable hash of the file contents.

    Args:
        path (str): the path to a file

    Returns:
        str: a hash of the file contents
    """
    contents = Path(path).read_bytes()
    return stable_hash(contents)

hash_objects

Attempt to hash objects by dumping to JSON or serializing with cloudpickle. On failure of both, None will be returned

Source code in prefect/utilities/hashing.py
def hash_objects(*args, **kwargs) -> Optional[str]:
    """
    Attempt to hash objects by dumping to JSON or serializing with cloudpickle.
    On failure of both, `None` will be returned
    """
    try:
        return stable_hash(json.dumps((args, kwargs), sort_keys=True))
    except Exception:
        pass

    try:
        return stable_hash(cloudpickle.dumps((args, kwargs)))
    except Exception:
        pass

    return None

stable_hash

Given some arguments, produces a stable 64-bit hash of their contents.

Supports bytes and strings. Strings will be UTF-8 encoded.

Parameters:

Name Description Default
*args

Items to include in the hash.

Union[str, bytes]
()

Returns:

Type Description
str

A hex hash.

Source code in prefect/utilities/hashing.py
def stable_hash(*args: Union[str, bytes]) -> str:
    """Given some arguments, produces a stable 64-bit hash of their contents.

    Supports bytes and strings. Strings will be UTF-8 encoded.

    Args:
        *args: Items to include in the hash.

    Returns:
        A hex hash.
    """
    h = hashlib.md5()
    for a in args:
        if isinstance(a, str):
            a = a.encode()
        h.update(a)
    return h.hexdigest()

to_qualified_name

Given an object, returns its fully-qualified name, meaning a string that represents its Python import path

Parameters:

Name Description Default
obj

an importable Python object

Any
required

Returns:

Type Description
str

the qualified name

Source code in prefect/utilities/hashing.py
def to_qualified_name(obj: Any) -> str:
    """
    Given an object, returns its fully-qualified name, meaning a string that represents its
    Python import path

    Args:
        obj (Any): an importable Python object

    Returns:
        str: the qualified name
    """
    return obj.__module__ + "." + obj.__qualname__