Kernel: Add comm handler to get Python env info

- This will be used from Spyder for a new status bar widget which will
display this info.
- Also add a test for it.

spyder_kernels/console/kernel.py

@@ -35,6 +35,13 @@
 from spyder_kernels.comms.frontendcomm import FrontendComm
 from spyder_kernels.comms.decorators import (
     register_comm_handlers, comm_handler)
+from spyder_kernels.utils.pythonenv import (
+    get_env_dir,
+    is_conda_env,
+    is_pyenv_env,
+    PythonEnvInfo,
+    PythonEnvType,
+)
 from spyder_kernels.utils.iofuncs import iofunctions
 from spyder_kernels.utils.mpl import automatic_backend, MPL_BACKENDS_TO_SPYDER
 from spyder_kernels.utils.nsview import (
@@ -81,6 +88,9 @@ def __init__(self, *args, **kwargs):
         # To track the interactive backend
         self.interactive_backend = None
 
+        # To save the python env info
+        self.pythonenv_info: PythonEnvInfo = {}
+
     @property
     def kernel_info(self):
         # Used for checking correct version by spyder
@@ -756,6 +766,29 @@ def update_syspath(self, path_dict, new_path_dict):
         else:
             os.environ.pop('PYTHONPATH', None)
 
+    @comm_handler
+    def get_pythonenv_info(self):
+        """Get the Python env info in which this kernel is installed."""
+        # We only need to compute this once
+        if not self.pythonenv_info:
+            path = sys.executable.replace("pythonw.exe", "python.exe")
+
+            if is_conda_env(pyexec=path):
+                env_type = PythonEnvType.Conda
+            elif is_pyenv_env(path):
+                env_type = PythonEnvType.PyEnv
+            else:
+                env_type = PythonEnvType.Custom
+
+            self.pythonenv_info = PythonEnvInfo(
+                path=path,
+                env_type=env_type,
+                name=get_env_dir(path, only_dir=True),
+                py_version='.'.join([str(n) for n in sys.version_info[:3]]),
+            )
+
+        return self.pythonenv_info
+
     # -- Private API ---------------------------------------------------
     # --- For the Variable Explorer
     def _get_len(self, var):

spyder_kernels/console/tests/test_console_kernel.py

@@ -31,10 +31,11 @@
 import numpy as np
 
 # Local imports
+from spyder_kernels.comms.commbase import CommBase
+from spyder_kernels.customize.spyderpdb import SpyderPdb
 from spyder_kernels.utils.iofuncs import iofunctions
+from spyder_kernels.utils.pythonenv import PythonEnvType
 from spyder_kernels.utils.test_utils import get_kernel, get_log_text
-from spyder_kernels.customize.spyderpdb import SpyderPdb
-from spyder_kernels.comms.commbase import CommBase
 
 # =============================================================================
 # Constants and utility functions
@@ -1410,5 +1411,26 @@ def test_hard_link_pdb(tmpdir):
     assert pdb_obj.canonic(str(d)) == pdb_obj.canonic(str(hard_link))
 
 
+@pytest.mark.skipif(not os.environ.get('CI'), reason="Only works on CIs")
+def test_get_pythonenv_info(kernel):
+    """Test the output we get from this method."""
+    output = kernel.get_pythonenv_info()
+    assert output["path"] == sys.executable
+
+    if os.environ.get('USE_CONDA'):
+        assert output["name"] == "test"
+        assert output["type"] == PythonEnvType.Conda
+    else:
+        assert output["type"] in [
+            # This Custom here accounts for Linux packagers that run our tests
+            # in their CIs
+            PythonEnvType.Custom,
+            PythonEnvType.Conda,
+        ]
+
+    # Check this key is present. Otherwise we'll break Spyder.
+    assert output["py_version"]
+
+
 if __name__ == "__main__":
     pytest.main()

spyder_kernels/utils/pythonenv.py

@@ -9,8 +9,27 @@
 """Utilities to get information about Python environments."""
 
 # Standard library imports
+from __future__ import annotations
 import os
 from pathlib import Path
+from typing import TypedDict
+
+
+class PythonEnvType:
+    """Enum with the different types of Python environments we can detect."""
+
+    Conda = "conda"
+    PyEnv = "pyenv"
+    Custom = "custom"  # Nor Conda or Pyenv
+
+
+class PythonEnvInfo(TypedDict):
+    """Schema for Python environment information."""
+
+    path: str
+    env_type: PythonEnvType
+    name: str
+    py_version: str
 
 
 def add_quotes(path):