def all_fm_negative_tomograms(*, include_private: bool = False) -> List[TomogramFile]:
    """
    Collect all `.rec` tomogram filepaths that have (probably, for now) been
    reviewed and do not have flagellar motors.

    Does not initially load the tomogram image data. Given a `Tomogram` called
    `tomo`, one can load and access the image data in one step with
    `tomo.get_data()`.

    **IN DEVELOPMENT** These results need to be manually checked.

    Args:
        include_private (bool): Whether to include our newest annotations, which
        should not be available to the public. Defaults to False.

    Returns:
        TomogramFile objects with no annotations attached.
    """
    tomograms = []

    # ~~~ DRIVE 1 ~~~ #
    # Hylemonella
    root = f"/grphome/grp_tomo_db1_d1/nobackup/archive/TomoDB1_d1/FlagellarMotor_P1/Hylemonella gracilis"
    dir_regex = re.compile(r"yc\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^fm.mod$", re.IGNORECASE)
    tomogram_regex = re.compile(r".*\.rec$")

    these_tomograms = seek_unannotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex]
    )
    tomograms += these_tomograms

    # ~~~ DRIVE 2 ~~~ #
    # Legionella
    root = f"/grphome/grp_tomo_db1_d2/nobackup/archive/TomoDB1_d2/FlagellarMotor_P2/legionella"
    dir_regex = re.compile(r"dg\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^FM\.mod$")
    tomogram_regex = re.compile(r".*SIRT_1k\.rec$")

    these_tomograms = seek_unannotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex]
    )
    tomograms += these_tomograms

    # Pseudomonas
    root = f"/grphome/grp_tomo_db1_d2/nobackup/archive/TomoDB1_d2/FlagellarMotor_P2/Pseudomonasaeruginosa/done"
    dir_regex = re.compile(r"ab\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^FM\.mod$")
    tomogram_regex = re.compile(r".*SIRT_1k\.rec$")

    these_tomograms = seek_unannotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex]
    )
    tomograms += these_tomograms

    # Proteus_mirabilis
    root = f"/grphome/grp_tomo_db1_d2/nobackup/archive/TomoDB1_d2/FlagellarMotor_P2/Proteus_mirabilis"
    dir_regex = re.compile(r"qya\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^FM\.mod$")
    tomogram_regex = re.compile(r".*\.rec$")

    these_tomograms = seek_unannotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex]
    )
    tomograms += these_tomograms

    # ~~~ DRIVE 3 ~~~ #
    # Bdellovibrio
    root = f"/grphome/grp_tomo_db1_d3/nobackup/archive/TomoDB1_d3/jhome_extra/Bdellovibrio_YW"
    dir_regex = re.compile(r"yc\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^flagellum_SIRT_1k\.mod$")
    tomogram_regex = re.compile(r".*SIRT_1k\.rec$")

    these_tomograms = seek_unannotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex]
    )
    tomograms += these_tomograms

    # Azospirillum
    root = f"/grphome/grp_tomo_db1_d3/nobackup/archive/TomoDB1_d3/jhome_extra/AzospirillumBrasilense/done"
    dir_regex = re.compile(r"ab\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^FM3\.mod$")
    tomogram_regex = re.compile(r".*SIRT_1k\.rec$")

    these_tomograms = seek_unannotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex]
    )
    tomograms += these_tomograms

    ### ANNOTATIONS BEYOND HERE ARE PRIVATE ###
    if not include_private:
        return tomograms

    # ~~~ ZHIPING ~~~ #
    root = f"/grphome/fslg_imagseg/nobackup/archive/zhiping_data/caulo_WT/"
    dir_regex = re.compile(r"rrb\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^flagellum\.mod$")
    tomogram_regex = re.compile(r".*\.rec$")

    these_tomograms = seek_unannotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex]
    )
    tomograms += these_tomograms

    # ~~~ ANNOTATION PARTY ~~~ #
    root = f"/grphome/grp_tomo_db1_d4/nobackup/archive/ExperimentRuns/"
    dir_regex = re.compile(r"(sma\d{4}.*)|(Vibrio.*)")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"flagellar_motor\.mod")
    tomogram_regex = re.compile(r".*\.mrc$")

    these_tomograms = seek_unannotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex]
    )
    tomograms += these_tomograms

    return tomograms

def all_fm_tomograms(*, include_private: bool = False) -> List[TomogramFile]:
    """
    Collect all pairs of `.rec` tomogram filepaths and flagellar motor `.mod`
    filepaths.

    Does not initially load the tomogram image data. Given a `Tomogram` called
    `tomo`, one can load and access the image data in one step with
    `tomo.get_data()`.

    Args:
        include_private (bool): Whether to include our newest annotations, which
        should not be available to the public. Defaults to False.

    Returns:
        TomogramFile objects with their annotations.
    """
    tomograms = []

    # ~~~ DRIVE 1 ~~~ #
    # Hylemonella
    root = f"/grphome/grp_tomo_db1_d1/nobackup/archive/TomoDB1_d1/FlagellarMotor_P1/Hylemonella gracilis"
    dir_regex = re.compile(r"yc\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^fm.mod$", re.IGNORECASE)
    tomogram_regex = re.compile(r".*\.rec$")

    these_tomograms = seek_annotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex], 
        ["Flagellar Motor"]
    )
    tomograms += these_tomograms

    # ~~~ DRIVE 2 ~~~ #
    # Legionella
    root = f"/grphome/grp_tomo_db1_d2/nobackup/archive/TomoDB1_d2/FlagellarMotor_P2/legionella"
    dir_regex = re.compile(r"dg\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^FM\.mod$")
    tomogram_regex = re.compile(r".*SIRT_1k\.rec$")

    these_tomograms = seek_annotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex], 
        ["Flagellar Motor"]
    )
    tomograms += these_tomograms

    # Pseudomonas
    root = f"/grphome/grp_tomo_db1_d2/nobackup/archive/TomoDB1_d2/FlagellarMotor_P2/Pseudomonasaeruginosa/done"
    dir_regex = re.compile(r"ab\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^FM\.mod$")
    tomogram_regex = re.compile(r".*SIRT_1k\.rec$")

    these_tomograms = seek_annotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex], 
        ["Flagellar Motor"]
    )
    tomograms += these_tomograms

    # Proteus_mirabilis
    root = f"/grphome/grp_tomo_db1_d2/nobackup/archive/TomoDB1_d2/FlagellarMotor_P2/Proteus_mirabilis"
    dir_regex = re.compile(r"qya\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^FM\.mod$")
    tomogram_regex = re.compile(r".*\.rec$")

    these_tomograms = seek_annotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex], 
        ["Flagellar Motor"]
    )
    tomograms += these_tomograms

    # ~~~ DRIVE 3 ~~~ #
    # Bdellovibrio
    root = f"/grphome/grp_tomo_db1_d3/nobackup/archive/TomoDB1_d3/jhome_extra/Bdellovibrio_YW"
    dir_regex = re.compile(r"yc\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^flagellum_SIRT_1k\.mod$")
    tomogram_regex = re.compile(r".*SIRT_1k\.rec$")

    these_tomograms = seek_annotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex], 
        ["Flagellar Motor"]
    )
    tomograms += these_tomograms

    # Azospirillum
    root = f"/grphome/grp_tomo_db1_d3/nobackup/archive/TomoDB1_d3/jhome_extra/AzospirillumBrasilense/done"
    dir_regex = re.compile(r"ab\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^FM3\.mod$")
    tomogram_regex = re.compile(r".*SIRT_1k\.rec$")

    these_tomograms = seek_annotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex], 
        ["Flagellar Motor"]
    )
    tomograms += these_tomograms

    ### ANNOTATIONS BEYOND HERE ARE PRIVATE ###
    if not include_private:
        return tomograms

    # ~~~ ZHIPING ~~~ #
    root = f"/grphome/fslg_imagseg/nobackup/archive/zhiping_data/caulo_WT/"
    dir_regex = re.compile(r"rrb\d{4}.*")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"^flagellum\.mod$")
    tomogram_regex = re.compile(r".*\.rec$")

    these_tomograms = seek_annotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex], 
        ["Flagellar Motor"]
    )
    tomograms += these_tomograms

    # ~~~ ANNOTATION PARTY ~~~ #
    root = f"/grphome/grp_tomo_db1_d4/nobackup/archive/ExperimentRuns/"
    dir_regex = re.compile(r"(sma\d{4}.*)|(Vibrio.*)")
    directories = seek_dirs(root, dir_regex)

    flagellum_regex = re.compile(r"flagellar_motor\.mod")
    tomogram_regex = re.compile(r".*\.mrc$")

    these_tomograms = seek_annotated_tomos(
        directories, 
        tomogram_regex, 
        [flagellum_regex], 
        ["Flagellar Motor"]
    )
    tomograms += these_tomograms

    return tomograms

def seek_annotated_tomos(
            directories: List[str], 
            tomo_regex: re.Pattern, 
            annotation_regexes: List[re.Pattern], 
            annotation_names: List[str]
        ) -> List[TomogramFile]:
    """
    Collect pairs of tomogram files and their corresponding annotation files,
    without loading the tomograms.

    Args:
        directories (list of str): List of directories to search for tomograms
        and annotations.

        tomo_regex (re.Pattern): The regex pattern to match tomogram filenames.

        annotation_regexes (list of re.Pattern): A list of regex patterns to
        match annotation filenames.

        annotation_names (list of str): A list of names for the annotations.

    Returns:
        TomogramFile objects with their corresponding annotations.
    """
    tomos = []
    for dir in directories:
        matches = seek_set(dir, [tomo_regex] + annotation_regexes)
        if matches is not None and None not in matches:
            tomogram_file = matches[0]
            annotation_files = matches[1:]
            annotations = []
            for (file, name) in zip(annotation_files, annotation_names):
                try:
                    annotations.append(AnnotationFile(file, name))
                except Exception as e:
                    print(f"An exception occured while loading `{file}`:\n{e}\n")
            tomo = TomogramFile(tomogram_file, annotations, load=False)
            tomos.append(tomo)
    return tomos

def seek_dirs(
            root: str, 
            regex: re.Pattern, 
            directories: Optional[List[str]] = None
        ) -> Union[List[str], None]:
    """Search for directories matching the given regex recursively within the
    specified root directory.

    Args:
        root (str): The root directory to start the search.

        regex (re.Pattern): The regex pattern to match the directory names.

        directories (list, optional): A list to accumulate matched directories.
        Should not be set in general usage, as this is used only for internal
        recursion. Defaults to None.

    Returns:
        A list of paths of matching directories.
    """
    if directories is None:
        directories = []
    for this_root, dirs, _ in os.walk(root):
        for dir in dirs:
            if regex.match(dir):
                directories.append(os.path.join(this_root, dir))
            else:
                directories = seek_dirs(dir, regex, directories)
    return directories

def seek_file(directory: str, regex: re.Pattern) -> Union[str, None]:
    """Search for a file matching the given regex recursively in the specified
    directory.

    Args:
        directory (str): The root directory to start the search. regex
        regex (re.Pattern): The regex pattern to match the filenames.

    Returns:
        The full path of the matching file, or None if no match is
        found.
    """
    for root, dirs, files in os.walk(directory):
        for file in files:
            if regex.match(file):
                return os.path.join(root, file)
        for dir in dirs:
            target = seek_file(dir, regex)
            if target is not None:
                return target
    return None

def seek_files(
        directory: str, 
        regex: re.Pattern, 
        files: Optional[List[str]] = None
    ) -> List[str]:
    """Search for all files matching the given regex recursively in the specified
    directory.

    Args:
        directory (str): The root directory to start the search. 

        regex (re.Pattern): The regex pattern to match the filenames.

        files (list, optional): A list to accumulate matched files.
        Should not be set in general usage, as this is used only for internal
        recursion. Defaults to None.

    Returns:
        A list of the full paths of each matching file.
    """
    if files is None:
        files = []
    for root, dirs, dir_files in os.walk(directory):
        for dir_file in dir_files:
            if regex.match(dir_file):
                files.append(os.path.join(root, dir_file))
        for dir in dirs:
            files = seek_files(os.path.join(root, dir), regex, files)
    return files

def seek_set(
            directory: str, 
            regexes: List[re.Pattern], 
            matches: List[str] = None
        ) -> Union[List[str], None]:
    """Recursively search the specified directory for exactly one match for each regex in the list.

    Args:
        directory (str): The directory to search.

        regexes (list of re.Pattern): A list of regex patterns to match filenames.

        matches (list, optional): A list to accumulate matches. Should not be
        set in general usage, as this is used only for internal recursion.
        Defaults to None.

    Returns:
        A list of matching file paths or None if extra matches are found.
    """
    if matches is None:
        matches = [None for _ in regexes]

    for root, dirs, files in os.walk(directory):
        for file in files:
            for r_idx, r in enumerate(regexes):
                if re.match(r, file):
                    if matches[r_idx] is None:
                        matches[r_idx] = os.path.join(root, file)
                    else:
                        return None  # Extra match found
    return matches

def seek_unannotated_tomos(
            directories: List[str], 
            tomo_regex: re.Pattern, 
            annotation_regexes: List[re.Pattern], 
        ) -> List[TomogramFile]:
    """
    Collect tomogram files that don't have annotations, without loading the
    tomograms.

    Args:
        directories (list of str): List of directories to search for tomograms
        and annotations.

        tomo_regex (re.Pattern): The regex pattern to match tomogram filenames.

        annotation_regexes (list of re.Pattern): A list of regex patterns. If
        any of these patterns find a match for one of the files in a given
        directory in `directories`, the tomogram in that directory will not be
        saved and returned. 

    Returns:
        TomogramFile objects.
    """
    tomos = []
    for dir in directories:
        matches = seek_set(dir, [tomo_regex] + annotation_regexes)

        if matches is not None and None not in matches:
            # This tomogram is annotated
            continue
        else:
            # Ensure that there is a tomogram in this directory
            tomo_candidates = seek_files(dir, tomo_regex)
            n_candidates = len(tomo_candidates)
            # If there are multiple possible unannotated tomogram candidates or
            # none here, that's an issue.
            if n_candidates > 1:
                warnings.warn(f"Multiple ({n_candidates}) unannotated tomograms in {dir} found. This may mean that the regular expression used to seek tomograms is not specific enough, or that this directory is strange.")
                continue
            elif n_candidates == 0:
                warnings.warn(f"No tomograms found in {dir}.")
                continue
            # If there is one candidate, it isn't annotated.
            else:
                # Append what must be the only unannotated tomogram candidate
                tomogram_file = tomo_candidates[0]
                tomo = TomogramFile(tomogram_file, load=False)
                tomos.append(tomo) 
    return tomos