Upon user's import plotly, we check core/optional requirements.

theengineear · theengineear · commit ed9be3eb20f6 · 2014-07-07T13:52:50.000-07:00
The goal here is to both issue warnings when requirements are not
installed and when requirements are not up to date.
diff --git a/plotly/__init__.py b/plotly/__init__.py
@@ -1,5 +1,56 @@
+import json
+import warnings
 from . version import __version__
 import graph_objs
 import plotly
 import tools
-import utils
+import utils
+
+from pkg_resources import resource_string
+
+
+def _check_for_requirements():
+    s = resource_string('plotly', 'requirements.json').decode('utf-8')
+
+    reqs = json.loads(s)
+
+    for req, version in reqs['core'].items():
+        try:
+            exec "import {}".format(req)
+        except ImportError:
+            warnings.warn(
+                "{} is a core requirement, you'll have to install it "
+                "on your machine before being able to use the plotly "
+                "package.".format(req))
+        else:
+            our_version = version.split('.')
+            exec "your_version = {}.__version__.split('.')".format(req)
+            for ours, yours in zip(our_version, your_version):
+                if int(ours) > int(yours):
+                    warnings.warn(
+                        "The core requirement, '{}', is on your "
+                        "machine, but it may be out of date. If you run "
+                        "into problems related to this package, "
+                        "you should try updating to the version we test "
+                        "with: '{}'. Your version: '{}'."
+                        "".format(req, version, ".".join(your_version)))
+
+    for req, version in reqs['optional'].items():
+        try:
+            exec "import {}".format(req)
+        except ImportError:
+            pass
+        else:
+            our_version = version.split('.')
+            exec "your_version = {}.__version__.split('.')".format(req)
+            for ours, yours in zip(our_version, your_version):
+                if int(ours) > int(yours):
+                    warnings.warn(
+                        "The optional requirement, '{}', is on your "
+                        "machine, but it may be out of date. If you run "
+                        "into problems related to this package, "
+                        "you should try updating to the version we test "
+                        "with: '{}'. Your version: '{}'."
+                        "".format(req, version, ".".join(your_version)))
+
+_check_for_requirements()
