Restrictions and known bugs¶

For Python development outside of a CP4D, for example with a Jupyter notebook outside of CP4D, you must use an Anaconda or Miniconda Python installation.
No support for nested parallel regions at sources, i.e. nested streamsx.topology.topology.Stream.set_parallel(), for example:
```
topo = Topology()
s = topo.source(S())
s.set_parallel(3).set_parallel(2)
```
In this example, set_parallel(3) is ignored.
When tuples are nested within other tuples in a stream schema, the call style of instances of StreamSchema for a callable is always dict, whatever value the style property has. When the return value of a callable represents also a structured schema with nested tuples, the return type must also be a dict. Otherwise the behaviour is not defined.

No schema support for container types (list, map, set, and the like) with non-primitive value or element types as value or element types for other containers, also when encapsulated in a named tuple:

class A_schema(typing.NamedTuple):
    x: int
    y: int

class B_schema(typing.NamedTuple):
    a_list: typing.List[A_schema]     # supported, A_schema does not contain a container type at all

class C_schema(typing.NamedTuple):
    c1: str
    c2: B_schema                      # supported, a container type can be nested at any depth

class D_schema(typing.NamedTuple):
    d1: str
    d2: typing.Mapping[int, typing.List[int]       # supported
    d3: typing.Mapping[int, typing.List[A_schema]  # not supported: a container with non-primitive element type is direct value type of a map

class E_schema(typing.NamedTuple):
    e1: bool
    e2: typing.Mapping[str, C_schema]   # not supported: C_schema.c2.a_list is a list with non-primitive element type

Schemas support only primitive types for the key type of a map:

class A_schema(typing.NamedTuple):
    a1: int
    a2: int

class B_schema(typing.NamedTuple):
    b1: str
    b2: typing.Mapping[str, A_schema]   # supported
    b3: typing.Mapping[A_schema, str]   # not supported, A_schema not supported as key type

Schemas support only primitive types as element type of a set:

class A_schema(typing.NamedTuple):
    a1: int
    a2: int

class B_schema(typing.NamedTuple):
    b1: int
    b2: typing.Set[int]       # supported
    b3: typing.Set[A_schema]  # not supported

Python Composites (derived from streamsx.topology.composite.Composite) can have only one input port.
No support to process final marker (end of stream) in Python Callables like in SPL operators
No hook for drain processing in consistent region for Python Callables
Submission time parameters, which are defined in SPL composites of other toolkits, or created by using streamsx.spl.op.Expression in the topology, cannot be accessed at runtime with streamsx.ec.get_submission_time_value(name).