add downloader

.style.yapf

+[style]
+based_on_style = pep8
+column_limit = 80

paddle_hub/downloader.py

+from urllib.request import urlretrieve
+from tqdm import tqdm
+
+import os
+import tempfile
+"""
+tqdm prograss hook
+"""
+
+
+class TqdmProgress(tqdm):
+    last_block = 0
+
+    def update_to(self, block_num=1, block_size=1, total_size=None):
+        '''
+        block_num  : int, optional
+            到目前为止传输的块 [default: 1].
+        block_size : int, optional
+            每个块的大小 (in tqdm units) [default: 1].
+        total_size : int, optional
+            文件总大小 (in tqdm units). 如果[default: None]保持不变.
+        '''
+        if total_size is not None:
+            self.total = total_size
+        self.update((block_num - self.last_block) * block_size)
+        self.last_block = block_num
+
+
+class DownloadManager(object):
+    def __init__(self):
+        self.dst_path = tempfile.mkstemp()
+
+    def download(self, link, dst_path):
+        file_name = link.split("/")[-1]
+        if dst_path is not None:
+            self.dst_path = dst_path
+        if not os.path.exists(self.dst_path):
+            os.makedirs(self.dst_path)
+        file_path = os.path.join(self.dst_path, file_name)
+        print("download filepath", file_path)
+
+        with TqdmProgress(
+                unit='B',
+                unit_scale=True,
+                unit_divisor=1024,
+                miniters=1,
+                desc=file_name) as progress:
+            path, header = urlretrieve(
+                link,
+                filename=file_path,
+                reporthook=progress.update_to,
+                data=None)
+
+            return path
+
+    def _extract_file(self, tgz, tarinfo, dst_path, buffer_size=10 << 20):
+        """Extracts 'tarinfo' from 'tgz' and writes to 'dst_path'."""
+        src = tgz.extractfile(tarinfo)
+        dst = tf.gfile.GFile(dst_path, "wb")
+        while 1:
+            buf = src.read(buffer_size)
+            if not buf:
+                break
+            dst.write(buf)
+            self._log_progress(len(buf))
+        dst.close()
+        src.close()
+
+    def download_and_uncompress(self, link, dst_path):
+        file_name = self.download(link, dst_path)
+        print(file_name)
+
+
+if __name__ == "__main__":
+    link = "ftp://nj03-rp-m22nlp062.nj03.baidu.com//home/disk0/chenzeyu01/movie/movie_summary.txt"
+    dl = DownloadManager()
+    dl.download_and_uncompress(link, "./tmp")