Issue in metpy imports

Question

I installed metpy with pip in order to plot a skewT diagram. I have the following issue when I try to import metpy packages:

File "/home/straussc/Documents/stage2A/observations/programmes/trace_skewT.py", line 10, in <module>
    import metpy.calc as mpcalc

  File "/home/straussc/.local/lib/python3.10/site-packages/metpy/__init__.py", line 15, in <module>
    from .xarray import *  # noqa: F401, F403, E402

  File "/home/straussc/.local/lib/python3.10/site-packages/metpy/xarray.py", line 31, in <module>
    from .units import (_mutate_arguments, DimensionalityError, is_quantity, UndefinedUnitError,

  File "/home/straussc/.local/lib/python3.10/site-packages/metpy/units.py", line 26, in <module>
    import pint

  File "/home/straussc/.local/lib/python3.10/site-packages/pint/__init__.py", line 28, in <module>
    from .formatting import formatter, register_unit_format

  File "/home/straussc/.local/lib/python3.10/site-packages/pint/formatting.py", line 20, in <module>
    from .babel_names import _babel_lengths, _babel_units

  File "/home/straussc/.local/lib/python3.10/site-packages/pint/babel_names.py", line 11, in <module>
    from .compat import HAS_BABEL

  File "/home/straussc/.local/lib/python3.10/site-packages/pint/compat.py", line 34, in <module>
    from typing_extensions import Self  # noqa

ImportError: cannot import name 'Self' from 'typing_extensions' (/usr/lib/python3/dist-packages/typing_extensions.py) 

Does someone understand where it comes from?

Answer 1

typing_extensions in your environment is outdated and in conflict with newer installs of pint, the units library MetPy relies on. Update the outdated package with

pip install --upgrade typing_extensions

and you should be good to go. There is an open issue to prevent this from happening in the future.