[ARTS-2.6] Improve catalog downloads (#924)

Display a progress bar during download.

When using an unreleased ARTS version, try to download the latest stable
catalogs.

environment-dev-linux.yml

@@ -27,6 +27,7 @@ dependencies:
         - sphinx
         - sphinx-favicon
         - sphinx_rtd_theme
+        - tqdm
         - xarray
         - zlib
         - mesa-libgl-devel-cos7-x86_64

environment-dev-mac.yml

@@ -23,6 +23,7 @@ dependencies:
         - sphinx
         - sphinx-favicon
         - sphinx_rtd_theme
+        - tqdm
         - xarray
         - zlib
 channels:

python/pyarts/cat/download.py

@@ -1,6 +1,14 @@
 import os
 import urllib.request
 import zipfile
+from tqdm import tqdm
+
+
+class _DownloadProgressBar(tqdm):
+    def update_to(self, b=1, bsize=1, tsize=None):
+        if tsize is not None:
+            self.total = tsize
+        return self.update(b * bsize - self.n)
 
 
 def _download_and_extract(url, extract_dir=".", verbose=False):
@@ -15,13 +23,27 @@ def _download_and_extract(url, extract_dir=".", verbose=False):
     if verbose:
         print(f"Downloading {url}")
     try:
-        zip_path, _ = urllib.request.urlretrieve(url)
+        with _DownloadProgressBar(
+            unit="B", unit_scale=True, miniters=1, desc=url.split("/")[-1]
+        ) as t:
+            zip_path, _ = urllib.request.urlretrieve(url, reporthook=t.update_to)
     except urllib.request.HTTPError as e:
         raise RuntimeError(f"Failed to download {url}: {e}")
     with zipfile.ZipFile(zip_path, "r") as f:
         f.extractall(extract_dir)
 
 
+def _get_latest_stable_version(version):
+    """
+    Decrement version to previous stable version.
+
+    Parameters:
+        version (str): Version string in format "major.minor.micro".
+    """
+    major, minor, micro = map(int, version.split("."))
+    return f"{major}.{minor}.{micro - 1 if micro % 2 else micro}"
+
+
 def retrieve(download_dir=None, version=None, verbose=False):
     """
     Download and extract the ARTS XML and catalog data files from github.
@@ -45,7 +67,15 @@ def retrieve(download_dir=None, version=None, verbose=False):
     """
     if version is None:
         from pyarts import __version__
-        version = __version__
+
+        version = _get_latest_stable_version(__version__)
+        if version != __version__:
+            if verbose:
+                print(
+                    f"No downloadable catalogs are available for development versions of ARTS.\n"
+                    f"Downloading the latest stable version {version} of the catalogs instead.\n"
+                    f"Check out the catalogs with svn if you need the latest development version."
+                )
 
     if download_dir is None:
         download_dir = os.path.join(os.getenv("HOME"), ".cache", "arts")
@@ -61,16 +91,15 @@ def retrieve(download_dir=None, version=None, verbose=False):
         if verbose:
             print("Skipping download, environment variable ARTS_INCLUDE_PATH already set.")
         return
-    if int(version[-1]) % 2:
-        raise RuntimeError(f"Version {version} is not a release version.\n"
-                           f"Please check out the current catalogs with svn instead.")
 
     def retrieve_catalog(catname):
         if not os.path.exists(os.path.join(download_dir, catname)):
             os.makedirs(download_dir, exist_ok=True)
             _download_and_extract(GITHUB_URL + catname + ".zip",
                                   download_dir,
                                   verbose=verbose)
+        elif verbose:
+            print(f"Skipping download, data already exists at {download_dir}/{catname}")
 
     retrieve_catalog(artsxmldata)
     retrieve_catalog(artscatdata)

python/setup.py

@@ -60,6 +60,7 @@ def has_ext_modules(foo):
         "numpy>=1.13",
         "scipy>=0.15.1",
         "setuptools>=0.7.2",
+        "tqdm",
     ],
     extras_require={
         "docs": ["sphinx_rtd_theme"],