poetry env use X.Y fails on Windows #2117
Description
-
I am on the latest Poetry version.
-
I have searched the issues of this repo and believe that this is not a duplicate.
-
If an exception occurs when executing a command, I executed it again in debug mode (
-vvvoption). -
OS version and name: Windows 10
-
Poetry version: 1.0.5
-
Link of a Gist with the contents of your pyproject.toml file: not needed
Issue
The shortcut command poetry env use X.Y to select the environment for Python X.Y, as documented in Managing environments, is broken in Windows. One is required instead to find, copy and paste the full path to Python executable.
Note that the documentation even says "especially Windows where pyenv is not available".
>poetry env use 3.7
'python3.7' is not recognized as an internal or external command,
operable program or batch file.
The reason is quite simple: CPython installation in Windows doesn't provide pythonX.Y.exe, so even if you have all of them in PATH, Poetry can only find the first one. They do, however, provide registry keys with installation locations, which Poetry can use to resolve X.Y to the Python interpreter path.
This piece of code should find the path to Python, given the version number as a X.Y string:
import os
try:
import winreg
except ImportError:
import _winreg as winreg
def find_python_interpreter(version):
for hkey, prefix in (
(winreg.HKEY_CURRENT_USER, "Software"),
(winreg.HKEY_CURRENT_USER, "Software\\WOW6432Node"),
(winreg.HKEY_LOCAL_MACHINE, "Software"),
(winreg.HKEY_LOCAL_MACHINE, "Software\\WOW6432Node"),
):
try:
value = winreg.QueryValue(hkey, "{}\\Python\\PythonCore\\{}\\InstallPath".format(prefix, version))
except FileNotFoundError:
continue
python = os.path.join(value, "python.exe")
if os.path.exists(python):
return python
return None
I have adjusted the code above to make it compatible with Python 2, but I have not tested afterwards, so please forgive any mistakes.