WIP: base64 encoding for numpy arrays

packages/python/plotly/_plotly_future_/b64_encoding.py

@@ -0,0 +1,5 @@
+from __future__ import absolute_import
+from _plotly_future_ import _future_flags, _assert_plotly_not_imported
+
+_assert_plotly_not_imported()
+_future_flags.add("b64_encoding")

packages/python/plotly/_plotly_utils/utils.py

@@ -3,12 +3,15 @@
 import sys
 import re
 from functools import reduce
+import base64
 
 from _plotly_utils.optional_imports import get_module
 from _plotly_utils.basevalidators import ImageUriValidator
+from _plotly_future_ import _future_flags
 
 
 PY36_OR_LATER = sys.version_info >= (3, 6)
+b64_encoding = "b64_encoding" in _future_flags
 
 
 def cumsum(x):
@@ -182,7 +185,9 @@ def encode_as_numpy(obj):
         if not numpy:
             raise NotEncodable
 
-        if obj is numpy.ma.core.masked:
+        if isinstance(obj, numpy.ndarray) and b64_encoding:
+            return b64_encode_numpy(obj)
+        elif obj is numpy.ma.core.masked:
             return float("nan")
         else:
             raise NotEncodable
@@ -227,6 +232,24 @@ class NotEncodable(Exception):
     pass
 
 
+def b64_encode_numpy(obj):
+    # Convert 1D numpy arrays with numeric types to memoryviews with
+    # datatype and shape metadata.
+    dtype = obj.dtype
+    if (
+        dtype.kind in ["u", "i", "f"]
+        and str(dtype) != "int64"
+        and str(dtype) != "uint64"
+    ):
+        # We have a numpy array that is compatible with JavaScript typed
+        # arrays
+        buffer = base64.b64encode(memoryview(obj.ravel(order="C"))).decode("utf-8")
+        return {"bvals": buffer, "dtype": str(dtype), "shape": obj.shape}
+    else:
+        # Convert all other numpy arrays to lists
+        return obj.tolist()
+
+
 def iso_to_plotly_time_string(iso_string):
     """Remove timezone info and replace 'T' delimeter with ' ' (ws)."""
     # make sure we don't send timezone info to plotly