def calc_class_weights_from_dataloader(
dataloader: 'torch.utils.data.DataLoader', num_classes: int,
data_dir: str) -> List[float]:
"""
Calculate the weights of each class to be used for weighted loss. This is similar to the function calc_class_weights
in text_classification_dataset, but it gets the labels from a dataloader rather than from a file.
Args:
dataloader: the dataloader for the training set
num_classes: number of classes in the dataset
"""
labels = []
for batch in dataloader:
labels.extend(tensor2list(batch[-1]))
logging.info(f'Calculating label frequency stats...')
total_sents, sent_label_freq, max_id = get_label_stats(
labels, os.path.join(data_dir, 'sentence_stats.tsv'), verbose=False)
if max_id >= num_classes:
raise ValueError(
f'Found an invalid label! Labels should be from [0, num_classes-1].'
)
class_weights_dict = get_freq_weights(sent_label_freq)
logging.info(f'Total Sentence Pairs: {total_sents}')
logging.info(f'Class Frequencies: {sent_label_freq}')
logging.info(f'Class Weights: {class_weights_dict}')
class_weights = fill_class_weights(weights=class_weights_dict,
max_id=num_classes - 1)
return class_weights
def calc_class_weights(file_path: str, num_classes: int):
"""
iterates over a data file and calculate the weights of each class to be used for class_balancing
Args:
file_path: path to the data file
num_classes: number of classes in the dataset
"""
if not os.path.exists(file_path):
raise FileNotFoundError(
f"Could not find data file {file_path} to calculate the class weights!"
)
with open(file_path, 'r') as f:
input_lines = f.readlines()
labels = []
for input_line in input_lines:
parts = input_line.strip().split()
try:
label = int(parts[-1])
except ValueError:
raise ValueError(
f'No numerical labels found for {file_path}. Labels should be integers and separated by [TAB] at the end of each line.'
)
labels.append(label)
logging.info(f'Calculating stats of {file_path}...')
total_sents, sent_label_freq, max_id = get_label_stats(
labels, f'{file_path}_sentence_stats.tsv', verbose=False)
if max_id >= num_classes:
raise ValueError(
f'Found an invalid label in {file_path}! Labels should be from [0, num_classes-1].'
)
class_weights_dict = get_freq_weights(sent_label_freq)
logging.info(f'Total Sentence: {total_sents}')
logging.info(f'Sentence class frequencies: {sent_label_freq}')
logging.info(f'Class Weights: {class_weights_dict}')
class_weights = fill_class_weights(weights=class_weights_dict,
max_id=num_classes - 1)
return class_weights
def get_label_ids(
label_file: str,
is_training: bool = False,
pad_label: str = 'O',
label_ids_dict: Dict[str, int] = None,
get_weights: bool = True,
class_labels_file_artifact='label_ids.csv',
):
"""
Generates str to int labels mapping for training data or checks correctness of the label_ids_dict
file for non-training files or if label_ids_dict is specified
Args:
label_file: the path of the label file to process
is_training: indicates whether the label_file is used for training
pad_label: token used for padding
label_ids_dict: str label name to int ids mapping. Required for non-training data.
If specified, the check that all labels from label_file are present in label_ids_dict will be performed.
For training data, if label_ids_dict is None, a new mapping will be generated from label_file.
get_weights: set to True to calculate class weights, required for Weighted Loss.
class_labels_file_artifact: name of the file to save in .nemo
"""
if not os.path.exists(label_file):
raise ValueError(f'File {label_file} was not found.')
logging.info(f'Processing {label_file}')
if not is_training and label_ids_dict is None:
raise ValueError(
f'For non training data, label_ids_dict created during preprocessing of the training data '
f'should be provided')
# collect all labels from the label_file
data_dir = os.path.dirname(label_file)
unique_labels = set(pad_label)
all_labels = []
with open(label_file, 'r') as f:
for line in f:
line = line.strip().split()
all_labels.extend(line)
unique_labels.update(line)
# check that all labels from label_file are present in the specified label_ids_dict
# or generate label_ids_dict from data (for training only)
save_label_ids = True
if label_ids_dict:
logging.info(f'Using provided labels mapping {label_ids_dict}')
save_label_ids = False
for name in unique_labels:
if name not in label_ids_dict:
raise ValueError(
f'{name} class from {label_file} not found in the provided mapping: {label_ids_dict}'
)
else:
label_ids_dict = {pad_label: 0}
if pad_label in unique_labels:
unique_labels.remove(pad_label)
for label in sorted(unique_labels):
label_ids_dict[label] = len(label_ids_dict)
label_ids_filename = os.path.join(data_dir, class_labels_file_artifact)
if is_training and save_label_ids:
with open(label_ids_filename, 'w') as f:
labels, _ = zip(
*sorted(label_ids_dict.items(), key=lambda x: x[1]))
f.write('\n'.join(labels))
logging.info(
f'Labels mapping {label_ids_dict} saved to : {label_ids_filename}')
# calculate label statistics
base_name = os.path.splitext(os.path.basename(label_file))[0]
stats_file = os.path.join(data_dir, f'{base_name}_label_stats.tsv')
if os.path.exists(stats_file) and not is_training and not get_weights:
logging.info(f'{stats_file} found, skipping stats calculation.')
else:
all_labels = [label_ids_dict[label] for label in all_labels]
logging.info(f'Three most popular labels in {label_file}:')
total_labels, label_frequencies, max_id = get_label_stats(
all_labels, stats_file)
logging.info(
f'Total labels: {total_labels}. Label frequencies - {label_frequencies}'
)
if get_weights:
class_weights_pkl = os.path.join(data_dir, f'{base_name}_weights.p')
if os.path.exists(class_weights_pkl):
class_weights = pickle.load(open(class_weights_pkl, 'rb'))
logging.info(f'Class weights restored from {class_weights_pkl}')
else:
class_weights_dict = get_freq_weights(label_frequencies)
logging.info(f'Class Weights: {class_weights_dict}')
class_weights = fill_class_weights(class_weights_dict, max_id)
pickle.dump(class_weights, open(class_weights_pkl, "wb"))
logging.info(f'Class weights saved to {class_weights_pkl}')
else:
class_weights = None
return label_ids_dict, label_ids_filename, class_weights
def __init__(
self,
data_dir: str,
modes: List[str] = ['train', 'test', 'dev'],
none_slot_label: str = 'O',
pad_label: int = -1,
):
if not if_exist(data_dir, ['dict.intents.csv', 'dict.slots.csv']):
raise FileNotFoundError(
"Make sure that your data follows the standard format "
"supported by JointIntentSlotDataset. Your data must "
"contain dict.intents.csv and dict.slots.csv.")
self.data_dir = data_dir
self.intent_dict_file = self.data_dir + '/dict.intents.csv'
self.slot_dict_file = self.data_dir + '/dict.slots.csv'
self.intents_label_ids = IntentSlotDataDesc.label2idx(
self.intent_dict_file)
self.num_intents = len(self.intents_label_ids)
self.slots_label_ids = IntentSlotDataDesc.label2idx(
self.slot_dict_file)
self.num_slots = len(self.slots_label_ids)
infold = self.data_dir
for mode in modes:
if not if_exist(self.data_dir, [f'{mode}.tsv']):
logging.info(f' Stats calculation for {mode} mode'
f' is skipped as {mode}.tsv was not found.')
continue
logging.info(f' Stats calculating for {mode} mode...')
slot_file = f'{self.data_dir}/{mode}_slots.tsv'
with open(slot_file, 'r') as f:
slot_lines = f.readlines()
input_file = f'{self.data_dir}/{mode}.tsv'
with open(input_file, 'r') as f:
input_lines = f.readlines()[1:] # Skipping headers at index 0
if len(slot_lines) != len(input_lines):
raise ValueError(
"Make sure that the number of slot lines match the "
"number of intent lines. There should be a 1-1 "
"correspondence between every slot and intent lines.")
dataset = list(zip(slot_lines, input_lines))
raw_slots, raw_intents = [], []
for slot_line, input_line in dataset:
slot_list = [int(slot) for slot in slot_line.strip().split()]
raw_slots.append(slot_list)
parts = input_line.strip().split()
raw_intents.append(int(parts[-1]))
logging.info(f'Three most popular intents in {mode} mode:')
total_intents, intent_label_freq, max_id = get_label_stats(
raw_intents, infold + f'/{mode}_intent_stats.tsv')
merged_slots = itertools.chain.from_iterable(raw_slots)
logging.info(f'Three most popular slots in {mode} mode:')
slots_total, slots_label_freq, max_id = get_label_stats(
merged_slots, infold + f'/{mode}_slot_stats.tsv')
logging.info(f'Total Number of Intents: {total_intents}')
logging.info(f'Intent Label Frequencies: {intent_label_freq}')
logging.info(f'Total Number of Slots: {slots_total}')
logging.info(f'Slots Label Frequencies: {slots_label_freq}')
if mode == 'train':
intent_weights_dict = get_freq_weights(intent_label_freq)
logging.info(f'Intent Weights: {intent_weights_dict}')
slot_weights_dict = get_freq_weights(slots_label_freq)
logging.info(f'Slot Weights: {slot_weights_dict}')
self.intent_weights = fill_class_weights(intent_weights_dict,
self.num_intents - 1)
self.slot_weights = fill_class_weights(slot_weights_dict,
self.num_slots - 1)
if pad_label != -1:
self.pad_label = pad_label
else:
if none_slot_label not in self.slots_label_ids:
raise ValueError(f'none_slot_label {none_slot_label} not '
f'found in {self.slot_dict_file}.')
self.pad_label = self.slots_label_ids[none_slot_label]
def __init__(
self,
data_dir: str,
modes: List[str] = ["train", "test", "dev"],
none_slot_label: str = "O",
pad_label: int = -1,
):
if not if_exist(data_dir, ["dict.intents.csv", "dict.slots.csv"]):
raise FileNotFoundError(
"Make sure that your data follows the standard format "
"supported by MultiLabelIntentSlotDataset. Your data must "
"contain dict.intents.csv and dict.slots.csv.")
self.data_dir = data_dir
self.intent_dict_file = self.data_dir + "/dict.intents.csv"
self.slot_dict_file = self.data_dir + "/dict.slots.csv"
self.intents_label_ids = get_labels_to_labels_id_mapping(
self.intent_dict_file)
self.num_intents = len(self.intents_label_ids)
self.slots_label_ids = get_labels_to_labels_id_mapping(
self.slot_dict_file)
self.num_slots = len(self.slots_label_ids)
infold = self.data_dir
for mode in modes:
if not if_exist(self.data_dir, [f"{mode}.tsv"]):
logging.info(f" Stats calculation for {mode} mode"
f" is skipped as {mode}.tsv was not found.")
continue
logging.info(f" Stats calculating for {mode} mode...")
slot_file = f"{self.data_dir}/{mode}_slots.tsv"
with open(slot_file, "r") as f:
slot_lines = f.readlines()
input_file = f"{self.data_dir}/{mode}.tsv"
with open(input_file, "r") as f:
input_lines = f.readlines()[1:] # Skipping headers at index 0
if len(slot_lines) != len(input_lines):
raise ValueError(
"Make sure that the number of slot lines match the "
"number of intent lines. There should be a 1-1 "
"correspondence between every slot and intent lines.")
dataset = list(zip(slot_lines, input_lines))
raw_slots, raw_intents = [], []
for slot_line, input_line in dataset:
slot_list = [int(slot) for slot in slot_line.strip().split()]
raw_slots.append(slot_list)
parts = input_line.strip().split("\t")[1:][0]
parts = list(map(int, parts.split(",")))
parts = [
1 if label in parts else 0
for label in range(self.num_intents)
]
raw_intents.append(tuple(parts))
logging.info(f"Three most popular intents in {mode} mode:")
total_intents, intent_label_freq, max_id = get_multi_label_stats(
raw_intents, infold + f"/{mode}_intent_stats.tsv")
merged_slots = itertools.chain.from_iterable(raw_slots)
logging.info(f"Three most popular slots in {mode} mode:")
slots_total, slots_label_freq, max_id = get_label_stats(
merged_slots, infold + f"/{mode}_slot_stats.tsv")
logging.info(f"Total Number of Intent Labels: {total_intents}")
logging.info(f"Intent Label Frequencies: {intent_label_freq}")
logging.info(f"Total Number of Slots: {slots_total}")
logging.info(f"Slots Label Frequencies: {slots_label_freq}")
if mode == "train":
intent_weights_dict = get_freq_weights_bce_with_logits_loss(
intent_label_freq)
logging.info(f"Intent Weights: {intent_weights_dict}")
slot_weights_dict = get_freq_weights(slots_label_freq)
logging.info(f"Slot Weights: {slot_weights_dict}")
self.intent_weights = fill_class_weights(intent_weights_dict,
self.num_intents - 1)
self.slot_weights = fill_class_weights(slot_weights_dict,
self.num_slots - 1)
if pad_label != -1:
self.pad_label = pad_label
else:
if none_slot_label not in self.slots_label_ids:
raise ValueError(f"none_slot_label {none_slot_label} not "
f"found in {self.slot_dict_file}.")
self.pad_label = self.slots_label_ids[none_slot_label]
def __init__(self,
data_dir: str,
modes: List[str] = ['train', 'test', 'dev'],
pad_label='O',
label_ids_dict=None):
"""A descriptor class that reads all the data and calculates some stats of the data and also calculates
the class weights to be used for class balancing
Args:
data_dir: the path to the data folder
modes: list of the modes to read, it can be from ["train", "test", "dev"] by default.
It is going to look for the data files at {data_dir}/{mode}.txt
label_ids_dict: labels to ids mapping from pretrained model
"""
self.data_dir = data_dir
self.label_ids = None
unique_labels = set()
for mode in modes:
all_labels = []
label_file = os.path.join(data_dir, 'labels_' + mode + '.txt')
if not os.path.exists(label_file):
logging.info(
f'Stats calculation for {mode} mode is skipped as {label_file} was not found.'
)
continue
with open(label_file, 'r') as f:
for line in f:
line = line.strip().split()
all_labels.extend(line)
unique_labels.update(line)
if mode == 'train':
label_ids = {pad_label: 0}
if pad_label in unique_labels:
unique_labels.remove(pad_label)
for label in sorted(unique_labels):
label_ids[label] = len(label_ids)
self.pad_label = pad_label
if label_ids_dict:
if len(set(label_ids_dict)
| set(label_ids)) != len(label_ids_dict):
raise ValueError(
f'Provided labels to ids map: {label_ids_dict} does not match the labels '
f'in the data: {label_ids}')
self.label_ids = label_ids_dict if label_ids_dict else label_ids
logging.info(f'Labels: {self.label_ids}')
self.label_ids_filename = os.path.join(data_dir,
'label_ids.csv')
out = open(self.label_ids_filename, 'w')
labels, _ = zip(
*sorted(self.label_ids.items(), key=lambda x: x[1]))
out.write('\n'.join(labels))
logging.info(f'Labels mapping saved to : {out.name}')
all_labels = [self.label_ids[label] for label in all_labels]
logging.info(f'Three most popular labels in {mode} dataset:')
total_labels, label_frequencies, max_id = get_label_stats(
all_labels, os.path.join(data_dir, mode + '_label_stats.tsv'))
logging.info(f'Total labels: {total_labels}')
logging.info(f'Label frequencies - {label_frequencies}')
if mode == 'train':
class_weights_dict = get_freq_weights(label_frequencies)
logging.info(f'Class Weights: {class_weights_dict}')
self.class_weights = fill_class_weights(
class_weights_dict, max_id)
self.num_classes = max_id + 1