daft.functions.count_matches#

def count_matches(
    expr: Expression,
    patterns: Any,
    *,
    whole_words: bool = False,
    case_sensitive: bool = True,
) -> Expression:
    """Counts the number of times a pattern, or multiple patterns, appear in a string.

    If whole_words is true, then matches are only counted if they are whole words. This
    also applies to multi-word strings. For example, on the string "abc def", the strings
    "def" and "abc def" would be matched, but "bc de", "abc d", and "abc " (with the space)
    would not.

    If case_sensitive is false, then case will be ignored. This only applies to ASCII
    characters; unicode uppercase/lowercase will still be considered distinct.

    Args:
        expr: The expression to check.
        patterns: A pattern or a list of patterns.
        whole_words: Whether to only match whole word(s). Defaults to false.
        case_sensitive: Whether the matching should be case sensitive. Defaults to true.

    Note:
        If a pattern is a substring of another pattern, the longest pattern is matched first.
        For example, in the string "hello world", with patterns "hello", "world", and "hello world",
        one match is counted for "hello world".
    """
    if isinstance(patterns, str):
        patterns = [patterns]
    if not isinstance(patterns, Expression):
        series = item_to_series("items", patterns)
        patterns = Expression._from_pyexpr(list_lit(series._series))

    return Expression._call_builtin_scalar_fn(
        "count_matches", expr, patterns, whole_words=whole_words, case_sensitive=case_sensitive
    )