Add mech for caching data

libcflib/expose_data.py

@@ -0,0 +1,42 @@
+import pathlib
+from requests_cache import CachedSession
+from ruamel import yaml
+
+
+class CachedData:
+    IMPORT_MAP_URL_TEMPLATE = "https://raw.githubusercontent.com/regro/libcfgraph/master/import_maps/{import_first_two_letters}.json"
+    FILE_LISTING_URL = (
+        "https://raw.githubusercontent.com/regro/libcfgraph/master/.file_listing.json"
+    )
+    HUBS_AUTHS_URL = "https://raw.githubusercontent.com/regro/cf-graph-countyfair/master/ranked_hubs_authorities.json"
+    DEFAULT_SESSION_SETTINGS = {
+        "cache_name": str(
+            pathlib.Path("~/.config/libcflib/cache_session.sqlite").absolute()
+        ),
+        "backend": "sqlite",
+        "exire_after": 60 * 60 * 1,
+    }
+
+    def __init__(self, session_kwargs=None):
+        if session_kwargs is None:
+            p = pathlib.Path("~/.config/libcflib/cache_session_kwargs.yaml").absolute()
+            if p.exists():
+                session_kwargs = yaml.load(p.open())
+            else:
+                session_kwargs = {}
+        _session_kwargs = self.DEFAULT_SESSION_SETTINGS.copy()
+        _session_kwargs.update(session_kwargs)
+        p = pathlib.Path(_session_kwargs["cache_name"])
+        p.mkdir(parents=True, exist_ok=True)
+        p.touch()
+        self.session = CachedSession(**_session_kwargs)
+
+    def _get(self, url):
+        return self.session.get(url).json()
+
+    def get_import_map(self, first_two_letters):
+        return self._get(
+            self.IMPORT_MAP_URL_TEMPLATE.format(
+                import_first_two_letters=first_two_letters
+            )
+        )

tests/test_expose_data.py

@@ -0,0 +1,16 @@
+import pathlib
+
+from libcflib.expose_data import CachedData
+
+
+def test_get_import_map(tmpdir):
+    cd = CachedData(session_kwargs={
+        'cache_name': str(pathlib.Path(tmpdir) / pathlib.Path('.config/libcflib/cache_session.sqlite')),
+        'backend': 'sqlite',
+        'exire_after': 60*60*1
+    })
+    first_two_letters = 'ma'
+    data = cd.get_import_map(first_two_letters)
+    assert 'matplotlib' in data
+    url = cd.IMPORT_MAP_URL_TEMPLATE.format(import_first_two_letters=first_two_letters)
+    assert cd.session.cache.has_url(url)