Hydrogen: No kernel for grammar python

[vader333]

Description:
Installed ipykernel and jupyter using:

python -m pip install ipykernel
python -m ipykernel install -user
pip install jupyter

When I update hydrogen kernels, it succeeds in finding ipykernel for Python 3

However, when I try to run hydrogen, there is no result, and if I try to restart the kernel, it says "No Kernel for Grammar Python"

When I run kernel jupyter kernelspec list --json, i get this:

{
  "kernelspecs": {
    "python3": {
      "resource_dir": "C:\\Users\\brian\\AppData\\Roaming\\jupyter\\kernels\\python3",
      "spec": {
        "argv": [
          "C:\\Users\\brian\\AppData\\Local\\Programs\\Python\\Python36\\python.exe",
          "-m",
          "ipykernel_launcher",
          "-f",
          "{connection_file}"
        ],
        "env": {},
        "display_name": "Python 3",
        "language": "Python"
      }
    }
  }
}

Versions:

Atom: 1.21.1 x64
Python 3.6.3 x64

[crazypenguin]

save your untitled file as .py file，does it works？

[vader333]

Oh, thank you for that suggestion. Apparently, I don't have python-language-server, which is required for hydrogen to work. When I saved it as a py file, it gave me that error, so I installed it, and after that, it worked. Thanks again!

[lgeiger]

Glad it's working now 🎉

Thanks @crazypenguin for helping debug.

Apparently, I don't have python-language-server, which is required for hydrogen to work

For the record, Hydrogen doesn't require python-language-server.
@vader333 You probably have ide-python installed which requires python-language-server as a external dependency.

@BenRussert We should check the behavior when trying to start a Kernel in a unsaved file. At least we should throw a helpful error message.