import urllib.request from pathlib import Path import streamlit as st # This code is based on https://github.com/streamlit/demo-self-driving/blob/230245391f2dda0cb464008195a470751c01770b/streamlit_app.py#L48 # noqa: E501 def download_file(url, download_to: Path, expected_size=None): # Don't download the file twice. # (If possible, verify the download using the file length.) if download_to.exists(): if expected_size: if download_to.stat().st_size == expected_size: return else: st.info(f"{url} is already downloaded.") if not st.button("Download again?"): return download_to.parent.mkdir(parents=True, exist_ok=True) # These are handles to two visual elements to animate. weights_warning, progress_bar = None, None try: weights_warning = st.warning("Downloading %s..." % url) progress_bar = st.progress(0) with open(download_to, "wb") as output_file: with urllib.request.urlopen(url) as response: length = int(response.info()["Content-Length"]) counter = 0.0 MEGABYTES = 2.0**20.0 while True: data = response.read(8192) if not data: break counter += len(data) output_file.write(data) # We perform animation by overwriting the elements. weights_warning.warning( "Downloading %s... (%6.2f/%6.2f MB)" % (url, counter / MEGABYTES, length / MEGABYTES) ) progress_bar.progress(min(counter / length, 1.0)) # Finally, we remove these visual elements by calling .empty(). finally: if weights_warning is not None: weights_warning.empty() if progress_bar is not None: progress_bar.empty()