Additionally, you could use pyobject.Code instead, as constructing types.CodeType is too complex and not compatible across multiple Python versions.

The pyobject library, which can be installed via pip install pyobject, provides a high-level wrapper for code objects.

For example:

>>> def f(a,b,c,*args):
...    print(a,b,c,args)
...
>>> c=Code.fromfunc(f)
>>> c.get_flags() # automatically parse them, not by manually calculating
['OPTIMIZED', 'NEWLOCALS', 'VARARGS']
>>> c.co_flags
7

The pyobject library has greatly changed, and pyobject versions since 1.2.4 has fixed the issue. pyobject · Github

Note: I'm the developer of pyobject.