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string_hashing

shortfx.fxString.string_hashing

String Hashing and Fingerprinting Functions.

This module provides functions for generating cryptographic hashes and normalized fingerprints from strings.

Key Features: - MD5, SHA-256, SHA-512 hashing - Normalized fingerprint for deduplication

Functions

fingerprint(text: str) -> str

Generates a normalized fingerprint for deduplication.

The fingerprint is created by lowercasing, removing accents, stripping non-alphanumeric characters, sorting the remaining tokens, and joining them with a single space.

Parameters:

Name Type Description Default
text str

The input string.

 required

Returns:

Type Description
str

A normalized fingerprint string suitable for comparing duplicates.
Example

fingerprint(" Café Résumé ") 'cafe resume' fingerprint("The LORD of The RINGS") 'lord of rings the'

Complexity: O(n log n) due to word sorting.

Source code in shortfx/fxString/string_hashing.py 
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def fingerprint(text: str) -> str:
    """Generates a normalized fingerprint for deduplication.

    The fingerprint is created by lowercasing, removing accents,
    stripping non-alphanumeric characters, sorting the remaining tokens,
    and joining them with a single space.

    Args:
        text: The input string.

    Returns:
        A normalized fingerprint string suitable for comparing duplicates.

    Example:
        >>> fingerprint("  Café  Résumé  ")
        'cafe resume'
        >>> fingerprint("The  LORD of The  RINGS")
        'lord of rings the'

    Complexity: O(n log n) due to word sorting.
    """
    if not text or not isinstance(text, str):
        return ""

    normalized = unicodedata.normalize("NFKD", text)
    ascii_text = normalized.encode("ascii", "ignore").decode("ascii")
    cleaned = re.sub(r"[^a-z0-9\s]", "", ascii_text.lower())
    words = sorted(cleaned.split())
    return " ".join(words)

hash_string(text: str, algorithm: str = 'sha256') -> str

Generates a hexadecimal hash digest of a string.

Parameters:

Name Type Description Default
text str

The input string to hash.

 required
algorithm str

Hash algorithm name — "md5", "sha256", or "sha512".

 'sha256'

Returns:

Type Description
str

The hexadecimal hash digest.

Raises:

Type Description
TypeError

If text is not a string.
ValueError

If algorithm is not supported.
Example

hash_string("hello") '2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824' hash_string("hello", "md5") '5d41402abc4b2a76b9719d911017c592'

Complexity: O(n)

Source code in shortfx/fxString/string_hashing.py 
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def hash_string(text: str, algorithm: str = "sha256") -> str:
    """Generates a hexadecimal hash digest of a string.

    Args:
        text: The input string to hash.
        algorithm: Hash algorithm name — "md5", "sha256", or "sha512".

    Returns:
        The hexadecimal hash digest.

    Raises:
        TypeError: If text is not a string.
        ValueError: If algorithm is not supported.

    Example:
        >>> hash_string("hello")
        '2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824'
        >>> hash_string("hello", "md5")
        '5d41402abc4b2a76b9719d911017c592'

    Complexity: O(n)
    """
    if not isinstance(text, str):
        raise TypeError("text must be a string")

    supported = {"md5", "sha256", "sha512"}

    if algorithm not in supported:
        raise ValueError(f"Unsupported algorithm '{algorithm}'. Use one of: {supported}")

    h = hashlib.new(algorithm)
    h.update(text.encode("utf-8"))
    return h.hexdigest()