map typesystem on python does not work

[gwenchee]

I am testing the a simple map typesystem for no_inst.py. An error is thrown when running a cyclus simulation.
State variable declaration in no_inst.py
test_out = ts.MapIntString( )

XML schema:
<test_out> <item> <key>3</key><val>POWER</val> </item> </test_out>

Cyclus output error:
AttributeError: 'list' object has no attribute 'encode' Exception ignored in: 'cyclus.typesystem.str_py_to_cpp' AttributeError: 'list' object has no attribute 'encode' XPath error : Invalid expression terminate called after throwing an instance of 'xmlpp::exception' what(): Invalid XPath: Aborted (core dumped)

[gwenchee]

I tried using a default value for the mapintstring in timeseries_inst
Example:
contract = ts.MapIntString( doc="The contract quantity and recipe", tooltip="Contract quantity and recipe", uilabel="Contract", default = {0,"helllo"} )

This throws the same error as before:
AttributeError: 'list' object has no attribute 'encode' Exception ignored in: 'cyclus.typesystem.str_py_to_cpp' AttributeError: 'list' object has no attribute 'encode' XPath error : Invalid expression terminate called after throwing an instance of 'xmlpp::exception' what(): Invalid XPath:

[gwenchee]

@FlanFlanagan @jbae11

[gwenchee]

The issue is in gentypesystem.py that generates typesystem.pyx in the std_string str_py_to_cpp function. An object list is being passed through it for map types. However, it is hard to pinpoint where the function is called and where the list object is passing to it

[gwenchee]

closed with #213

[gwenchee]

more explanation: #212