DEPR: deprecate fetch_nb_dependencies and demote requests to an extra

pyproject.toml

@@ -25,11 +25,15 @@ requires-python = ">=3.7"
 dependencies = [
     'numba>=0.56.0',
     'numpy>=1.17.0',
-    'requests',
     'scipy>=1.5.0',
 ]
 
 [project.optional-dependencies]
+# Supports the deprecated quantecon.util.notebooks helpers; removed in v1.0
+# together with the module itself.
+notebooks = [
+    "requests",
+]
 testing = [
     "pytest",
     "coverage",

quantecon/util/notebooks.py

@@ -11,15 +11,18 @@
 
 "https://github.com/QuantEcon/QuantEcon.notebooks/raw/master/dependencies/mpi/something.py" --> ./something.py
 
-TODO
-----
-1. Write Style guide for QuantEcon.notebook contributions
-2. Write an interface for Dat Server
-3. Platform Agnostic (replace wget usage)
+.. deprecated:: 0.12.0
+    ``fetch_nb_dependencies`` is deprecated and will be removed in v1.0, along
+    with this module. It has no remaining callers in the QuantEcon lecture
+    series, and ``requests`` is no longer a mandatory dependency of
+    QuantEcon.py. Datasets referenced by the lectures live in
+    `QuantEcon/data-lectures <https://github.com/QuantEcon/data-lectures>`_ and
+    should be fetched by stable URL with the tool of your choice.
 
 """
 
 import os
+import warnings
 
 #-Remote Structure-#
 REPO = "https://github.com/QuantEcon/QuantEcon.notebooks"
@@ -32,6 +35,11 @@
 def fetch_nb_dependencies(files, repo=REPO, raw=RAW, branch=BRANCH, folder=FOLDER, overwrite=False, verbose=True):
     """
     Retrieve raw files from QuantEcon.notebooks or other Github repo
+
+    .. deprecated:: 0.12.0
+        Deprecated and will be removed in v1.0. Fetch data by stable URL from
+        `QuantEcon/data-lectures <https://github.com/QuantEcon/data-lectures>`_
+        instead.
 
     Parameters
     ----------
@@ -71,7 +79,22 @@ def fetch_nb_dependencies(files, repo=REPO, raw=RAW, branch=BRANCH, folder=FOLDE
     by setting ``overwrite=True``.
 
     """
-    import requests
+    warnings.warn(
+        "`fetch_nb_dependencies` is deprecated and will be removed in v1.0. "
+        "Fetch data by stable URL from QuantEcon/data-lectures instead.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+
+    try:
+        import requests
+    except ImportError:                                   # pragma: no cover
+        raise ImportError(
+            "`fetch_nb_dependencies` requires `requests`, which is no longer a "
+            "mandatory dependency of QuantEcon.py. Install it with "
+            "`pip install 'quantecon[notebooks]'`. This function is deprecated "
+            "and will be removed in v1.0."
+        )
 
     #-Generate Common Data Structure-#
     if type(files) == list:
@@ -99,6 +122,8 @@ def fetch_nb_dependencies(files, repo=REPO, raw=RAW, branch=BRANCH, folder=FOLDE
             #-Get file in OS agnostic way using requests-#
             url = "/".join([repo, raw, branch, folder, fl])
             r = requests.get(url)
+            #-Do not write an error page to disk under the requested name (#870)-#
+            r.raise_for_status()
             with open(fl, "wb") as fl:
                 fl.write(r.content)
             status.append(True)

quantecon/util/tests/test_notebooks.py

@@ -9,6 +9,7 @@
 
 from quantecon.util import fetch_nb_dependencies
 import os
+import pytest
 
 FILES = ['test_file.md']
 REPO = "https://github.com/QuantEcon/QuantEcon.py"
@@ -17,6 +18,7 @@
 FOLDER = "quantecon/util/tests/"
 
 
+@pytest.mark.filterwarnings("ignore::DeprecationWarning")
 class TestNotebookUtils:
 
     def test_fetch_nb_dependencies(self):
@@ -39,3 +41,16 @@ def test_fetch_nb_dependencies_overwrite(self):
 
     def teardown_method(self):
         os.remove("test_file.md")
+
+
+class TestNotebookUtilsDeprecation:
+    """`fetch_nb_dependencies` is deprecated in 0.12.0 and removed in v1.0."""
+
+    def test_fetch_nb_dependencies_warns(self):
+        with pytest.warns(DeprecationWarning, match="removed in v1.0"):
+            fetch_nb_dependencies(
+                files=FILES, repo=REPO, raw=RAW, branch=BRANCH, folder=FOLDER)
+
+    def teardown_method(self):
+        if os.path.isfile("test_file.md"):
+            os.remove("test_file.md")