problem in output of a function

[snippsat]

? what does co_names do? where can I get more info about it?

It's an attribute(method) of built-in compile().
So if want look more at it has to look tutorials about compile(),
and not .co_names alone which is just one method.

>>> code = compile('print(55)', 'test', 'eval')
>>> exec(code)
55

# Use a couple of methods 
>>> code.co_names
('print',)
>>> code.co_code
b'\x97\x00\x02\x00e\x00d\x00\xa6\x01\x00\x00\xab\x01\x00\x00\x00\x00\x00\x00\x00\x00S\x00'

# All 
>>> [i for i in dir(code) if not i.startswith('__')]
['_co_code_adaptive', '_varname_from_oparg', 'co_argcount', 'co_cellvars', 'co_code',
'co_consts', 'co_exceptiontable', 'co_filename', 'co_firstlineno', 'co_flags', 'co_freevars',
'co_kwonlyargcount', 'co_lines', 'co_linetable', 'co_lnotab', 'co_name', 'co_names', 'co_nlocals',
'co_positions', 'co_posonlyargcount', 'co_qualname', 'co_stacksize', 'co_varnames', 'replace']

# look at help for compile
>>> help(compile)
Help on built-in function compile in module builtins:

compile(source, filename, mode, flags=0, dont_inherit=False, optimize=-1, *, _feature_version=-1)
    Compile source into a code object that can be executed by exec() or eval().

    The source code may represent a Python module, statement or expression.
    The filename will be used for run-time error messages.
    The mode must be 'exec' to compile a module, 'single' to compile a
    single (interactive) statement, or 'eval' to compile an expression.
    The flags argument, if present, controls which future statements influence
    the compilation of the code.
    The dont_inherit argument, if true, stops the compilation inheriting
    the effects of any future statements in effect in the code calling
    compile; if absent or false these statements do influence the compilation,
    in addition to any features explicitly specified.