expression.py 文件源码

def _peval_comprehension_generators(state, generators, ctx):
    if len(generators) == 0:
        return state, []

    generator = generators[0]
    next_generators = generators[1:]

    state, iter_result = _peval_expression(state, generator.iter, ctx)

    masked_bindings = _get_masked_bindings(generator.target, ctx.bindings)
    masked_ctx = ctx.set('bindings', masked_bindings)

    state, ifs_result = _peval_comprehension_ifs(state, generator.ifs, masked_ctx)

    if is_known_value(ifs_result):
        success, bool_value = try_call(bool, args=(ifs_result.value,))
        if success and bool_value:
            ifs_result = []

    state, new_generator_kwds = map_reify(
        state, dict(target=generator.target, iter=iter_result, ifs=ifs_result))
    new_generator = ast.comprehension(**new_generator_kwds)

    state, new_generators = _peval_comprehension_generators(state, next_generators, ctx)

    return state, [new_generator] + new_generators