Search for strings in iterables and Pandas DataFrames

search_strings.py

def str_search(*substrings: str, iterable, exact_match: bool = False) -> list:
    """Case-insensitive search of an iterable for substrings.

    Args:
        substrings (str): strings to search for in the iterable.
        iterable (list, tuple, etc): iterable containing string objects to be
            searched.
        exact_match (bool): if True only return a single value that exactly
            matches the substring supplied (therefore only works if 1 substring
            arg is supplied). Otherwise returns list of all partial matches.
    """
    lower_to_real = {str.lower(i): i for i in iterable if isinstance(i, str)}
    strings = [str.lower(s) for s in substrings if isinstance(s, str)]
    if exact_match:
        try:
            match = [v for k, v in lower_to_real.items() if all([s == k for s in strings])][0]
        except IndexError:
            return list()
    else:
        match = [v for k, v in lower_to_real.items() if all([s in k for s in strings])]
    return match


def str_search_df(*keywords, df):
    """Search all columns of a Pandas DataFrame for strings matching keywords.
    """
    mask = (~df.index.isin(list(df.index)))
    for col in df.columns:
        matches = str_search(*keywords, iterable=df[col].astype(str))
        if len(matches):
            mask = mask | (df[col].isin(matches))
    return df[mask]