import collections (dynamic class targeting EASY FIX)

[arcman7]

Context: I am using Transcrypt to convert the code in this repository: https://github.com/deepmind/pysc2 to javascript.

Problem: I can't import collections, therefore I cant target the classes that are generated by collections, for example:

class Feature(collections.namedtuple(
    "Feature", ["index", "name", "layer_set", "full_name", "scale", "type",
                "palette", "clip"])):

Solution: Create a local copy of 'collections' module in a file named collections.py. Modify the namedtuple function to print the class or write the stringified class template to a target directory. I took the code from collections (python version 2) to make the following method:

def print_class(typename, field_names):
    numfields = len(field_names)
    argtxt = repr(field_names).replace("'", "")[1:-1]   # tuple repr without parens or quotes
    reprtxt = ', '.join('%s=%%r' % name for name in field_names)
    template = '''class %(typename)s(tuple):
        '%(typename)s(%(argtxt)s)' \n
        __slots__ = () \n
        _fields = %(field_names)r \n
        def __new__(_cls, %(argtxt)s):
            'Create new instance of %(typename)s(%(argtxt)s)'
            return _tuple.__new__(_cls, (%(argtxt)s)) \n
        @classmethod
        def _make(cls, iterable, new=tuple.__new__, len=len):
            'Make a new %(typename)s object from a sequence or iterable'
            result = new(cls, iterable)
            if len(result) != %(numfields)d:
                raise TypeError('Expected %(numfields)d arguments, got %%d' %% len(result))
            return result \n
        def __repr__(self):
            'Return a nicely formatted representation string'
            return '%(typename)s(%(reprtxt)s)' %% self \n
        def _asdict(self):
            'Return a new OrderedDict which maps field names to their values'
            return OrderedDict(zip(self._fields, self)) \n
        def _replace(_self, **kwds):
            'Return a new %(typename)s object replacing specified fields with new values'
            result = _self._make(map(kwds.pop, %(field_names)r, _self))
            if kwds:
                raise ValueError('Got unexpected field names: %%r' %% kwds.keys())
            return result \n
        def __getnewargs__(self):
            'Return self as a plain tuple.  Used by copy and pickle.'
            return tuple(self) \n\n''' % locals()
    for i, name in enumerate(field_names):
        template += "        %s = _property(_itemgetter(%d), doc='Alias for field number %d')\n" % (name, i, i)
  
    print(template)

The function print_class is called inside the namedtuple method inside of the collections.py file. This way, anytime a class is dynamically generated at run time, I can then go back and target the classes that the collections module would have been using internally. Easy peasy.

I know its hacky as hell, but it got the job done. And I believe that this approach could be used to ease the burden of developers utilizing Transcrypt to develop javascript projects from existing python projects.

[arcman7]

I'll leave this issue open in case you want to triage it or something, but I'm giving up on using transcrypt for my project. Not being able to make use of a number of core python modules has made this basically impossible. Being able to use operator.py (import operator) would be a huge step for this project imo.

Cheers!