TransformerGroup does not handle cases where both the allow_superseded and always_xy user arguments is used

[phaarnes]

Example code

Ex. 1 TransformerGroup fails to list up available transformations when specifying both always_xy and allow_superseded

from pyproj.transformer import TransformerGroup
TransformerGroup("EPSG:4230", "EPSG:4326", allow_superseded=True, always_xy=True).transformers

Outputs:

Traceback (most recent call last):
  File "/usr/local/lib/python3.11/site-packages/pyproj/transformer.py", line 207, in __init__
    super().__init__(
  File "pyproj/_transformer.pyx", line 241, in pyproj._transformer._TransformerGroup.__init__
  File "pyproj/_transformer.pyx", line 602, in pyproj._transformer._Transformer._from_pj
  File "pyproj/_transformer.pyx", line 653, in pyproj._transformer._Transformer._init_from_crs
  File "pyproj/_transformer.pyx", line 359, in pyproj._transformer._Transformer._initialize_from_projobj
pyproj.exceptions.ProjError: Input is not a transformation.

Ex.2 TransformerGroup should return 36 available transformations when allow_superseded not defined

ct_lst = TransformerGroup("EPSG:4230", "EPSG:4326").transformers
print(len(ct_lst))

Outputs:

36

Ex.3 TransformerGroup should return 37 available transformations when allow_superseded is set to True

ct_lst = TransformerGroup("EPSG:4230", "EPSG:4326", allow_superseded=True).transformers
print(len(ct_lst))

Outputs:

37

ct_lst = TransformerGroup("EPSG:4230", "EPSG:4326", allow_superseded=True).transformers
print(len(ct_lst))

Problem description

TransformerGroup fails to a create a list of all available transformation objects when the user set both always_xy and allow_superseded equals True.

Environment Information

pyproj version 3.6.1
python 3.11

Installation method

pip wheel

[phaarnes]

An issue is created in PyProj GitHub repo.

[rouault]

This feels more like a pyproj bug, than a PROJ one. At least the exception comes from https://github.com/pyproj4/pyproj/blob/42aa92f489bd266749a44cb78101eae28e20f5c3/pyproj/_transformer.pyx#L341

[phaarnes]

Hi Even,
I see. Feel free to delete this issue if you think its only related to pyproj