Fix non printable ASCII characters getting recognised as stringlike (#…

…246)

This workaround will be rendered unnecessary once OpenCyphal/specification#51 is implemented.

pycyphal/_version.py

@@ -1 +1 @@
-__version__ = "1.10.1"
+__version__ = "1.10.2"

pycyphal/dsdl/_builtin_form.py

@@ -1,7 +1,7 @@
 # Copyright (c) 2019 OpenCyphal
 # This software is distributed under the terms of the MIT License.
 # Author: Pavel Kirienko <pavel@opencyphal.org>
-
+import string
 import typing
 import logging
 import numpy
@@ -60,7 +60,9 @@ def _to_builtin_impl(
 
     if isinstance(model, pydsdl.ArrayType):
         assert isinstance(obj, numpy.ndarray)
-        if model.string_like:  # TODO: drop this special case when strings are natively supported in DSDL.
+        # TODO: drop this special case when strings are natively supported in DSDL.
+        printable = set(map(ord, string.printable))
+        if model.string_like and all(map(lambda x: x in printable, obj.tobytes())):
             try:
                 return bytes(e for e in obj).decode()
             except UnicodeError:

tests/dsdl/_builtin_form.py

@@ -59,7 +59,7 @@ def _unittest_slow_builtin_form_manual(compiled: typing.List[pycyphal.dsdl.Gener
         "name": "org.node.my",
         "software_image_crc": [0x0DDDEADB16B00B5],
         # The following will have to be changed when strings are supported natively in DSDL:
-        "certificate_of_authenticity": bytes(range(100)).decode(),
+        "certificate_of_authenticity": list(range(100)),
     }
 
     bi = pycyphal.dsdl.to_builtin(