Source code for torchtext.utils
import torch
import csv
import hashlib
import os
import tarfile
import logging
import sys
import zipfile
import gzip
from ._download_hooks import _DATASET_DOWNLOAD_MANAGER
from torchtext import _CACHE_DIR
[docs]def reporthook(t):
"""
https://github.com/tqdm/tqdm.
"""
last_b = [0]
def inner(b=1, bsize=1, tsize=None):
"""
b: int, optional
Number of blocks just transferred [default: 1].
bsize: int, optional
Size of each block (in tqdm units) [default: 1].
tsize: int, optional
Total size (in tqdm units). If [default: None] remains unchanged.
"""
if tsize is not None:
t.total = tsize
t.update((b - last_b[0]) * bsize)
last_b[0] = b
return inner
def validate_file(file_obj, hash_value, hash_type="sha256"):
"""Validate a given file object with its hash.
Args:
file_obj: File object to read from.
hash_value (str): Hash for url.
hash_type (str, optional): Hash type, among "sha256" and "md5" (Default: ``"sha256"``).
Returns:
bool: return True if its a valid file, else False.
"""
if hash_type == "sha256":
hash_func = hashlib.sha256()
elif hash_type == "md5":
hash_func = hashlib.md5()
else:
raise ValueError
while True:
# Read by chunk to avoid filling memory
chunk = file_obj.read(1024 ** 2)
if not chunk:
break
hash_func.update(chunk)
return hash_func.hexdigest() == hash_value
def _check_hash(path, hash_value, hash_type):
logging.info('Validating hash {} matches hash of {}'.format(hash_value, path))
with open(path, "rb") as file_obj:
if not validate_file(file_obj, hash_value, hash_type):
raise RuntimeError("The hash of {} does not match. Delete the file manually and retry.".format(os.path.abspath(path)))
[docs]def download_from_url(url, path=None, root='.data', overwrite=False, hash_value=None,
hash_type="sha256"):
"""Download file, with logic (from tensor2tensor) for Google Drive. Returns
the path to the downloaded file.
Args:
url: the url of the file from URL header. (None)
path: path where file will be saved
root: download folder used to store the file in (.data)
overwrite: overwrite existing files (False)
hash_value (str, optional): hash for url (Default: ``None``).
hash_type (str, optional): hash type, among "sha256" and "md5" (Default: ``"sha256"``).
Examples:
>>> url = 'http://www.quest.dcs.shef.ac.uk/wmt16_files_mmt/validation.tar.gz'
>>> torchtext.utils.download_from_url(url)
>>> url = 'http://www.quest.dcs.shef.ac.uk/wmt16_files_mmt/validation.tar.gz'
>>> torchtext.utils.download_from_url(url)
>>> '.data/validation.tar.gz'
"""
# figure out filename and root
if path is None:
_, filename = os.path.split(url)
root = os.path.abspath(root)
path = os.path.join(root, filename)
else:
path = os.path.abspath(path)
root, filename = os.path.split(os.path.abspath(path))
# skip download if path exists and overwrite is not True
if os.path.exists(path):
logging.info('File %s already exists.' % path)
if not overwrite:
if hash_value:
_check_hash(path, hash_value, hash_type)
return path
# make root dir if does not exist
if not os.path.exists(root):
try:
os.makedirs(root)
except OSError:
raise OSError("Can't create the download directory {}.".format(root))
# download data and move to path
_DATASET_DOWNLOAD_MANAGER.get_local_path(url, destination=path)
logging.info('File {} downloaded.'.format(path))
# validate
if hash_value:
_check_hash(path, hash_value, hash_type)
# all good
return path
[docs]def unicode_csv_reader(unicode_csv_data, **kwargs):
r"""Since the standard csv library does not handle unicode in Python 2, we need a wrapper.
Borrowed and slightly modified from the Python docs:
https://docs.python.org/2/library/csv.html#csv-examples
Args:
unicode_csv_data: unicode csv data (see example below)
Examples:
>>> from torchtext.utils import unicode_csv_reader
>>> import io
>>> with io.open(data_path, encoding="utf8") as f:
>>> reader = unicode_csv_reader(f)
"""
# Fix field larger than field limit error
maxInt = sys.maxsize
while True:
# decrease the maxInt value by factor 10
# as long as the OverflowError occurs.
try:
csv.field_size_limit(maxInt)
break
except OverflowError:
maxInt = int(maxInt / 10)
csv.field_size_limit(maxInt)
for line in csv.reader(unicode_csv_data, **kwargs):
yield line
def utf_8_encoder(unicode_csv_data):
for line in unicode_csv_data:
yield line.encode('utf-8')
[docs]def extract_archive(from_path, to_path=None, overwrite=False):
"""Extract archive.
Args:
from_path: the path of the archive.
to_path: the root path of the extracted files (directory of from_path)
overwrite: overwrite existing files (False)
Returns:
List of paths to extracted files even if not overwritten.
Examples:
>>> url = 'http://www.quest.dcs.shef.ac.uk/wmt16_files_mmt/validation.tar.gz'
>>> from_path = './validation.tar.gz'
>>> to_path = './'
>>> torchtext.utils.download_from_url(url, from_path)
>>> torchtext.utils.extract_archive(from_path, to_path)
>>> ['.data/val.de', '.data/val.en']
>>> torchtext.utils.download_from_url(url, from_path)
>>> torchtext.utils.extract_archive(from_path, to_path)
>>> ['.data/val.de', '.data/val.en']
"""
if to_path is None:
to_path = os.path.dirname(from_path)
if from_path.endswith(('.tar.gz', '.tgz')):
logging.info('Opening tar file {}.'.format(from_path))
with tarfile.open(from_path, 'r') as tar:
files = []
for file_ in tar:
file_path = os.path.join(to_path, file_.name)
if file_.isfile():
files.append(file_path)
if os.path.exists(file_path):
logging.info('{} already extracted.'.format(file_path))
if not overwrite:
continue
tar.extract(file_, to_path)
logging.info('Finished extracting tar file {}.'.format(from_path))
return files
elif from_path.endswith('.zip'):
assert zipfile.is_zipfile(from_path), from_path
logging.info('Opening zip file {}.'.format(from_path))
with zipfile.ZipFile(from_path, 'r') as zfile:
files = []
for file_ in zfile.namelist():
file_path = os.path.join(to_path, file_)
files.append(file_path)
if os.path.exists(file_path):
logging.info('{} already extracted.'.format(file_path))
if not overwrite:
continue
zfile.extract(file_, to_path)
files = [f for f in files if os.path.isfile(f)]
logging.info('Finished extracting zip file {}.'.format(from_path))
return files
elif from_path.endswith('.gz'):
logging.info('Opening gz file {}.'.format(from_path))
default_block_size = 65536
filename = from_path[:-3]
files = [filename]
with gzip.open(from_path, 'rb') as gzfile, \
open(filename, 'wb') as d_file:
while True:
block = gzfile.read(default_block_size)
if not block:
break
else:
d_file.write(block)
d_file.write(block)
logging.info('Finished extracting gz file {}.'.format(from_path))
return files
else:
raise NotImplementedError(
"We currently only support tar.gz, .tgz, .gz and zip achives.")
def _log_class_usage(klass):
identifier = "torchtext"
if klass and hasattr(klass, "__name__"):
identifier += f".{klass.__name__}"
torch._C._log_api_usage_once(identifier)
def get_asset_local_path(asset_path: str) -> str:
"""Get local path for assets. Download if path does not exost locally
Args:
asset_path: Local path to asset or remote URL
Returns:
bool: local path of the asset after downloading or reading from cache
Examples:
>>> url = 'http://<HOST>/file.txt'
>>> torchtext.utils.get_asset_local_path(url)
>>> '.data/file.txt'
>>> torchtext.utils.get_asset_local_path('/home/user/file.txt')
>>> '/home/user/file.txt'
"""
if os.path.exists(asset_path):
local_path = asset_path
else:
local_path = download_from_url(url=asset_path, root=_CACHE_DIR)
return local_path
