There was a related issue, which was closed https://bugs.python.org/issue26715.

If virtual environment was activated using Powershell script - Activate.ps1, the Deactivate.ps1 was not created, while the documentation says that it should.

"You can deactivate a virtual environment by typing “deactivate” in your shell. The exact mechanism is platform-specific: for example, the Bash activation script defines a “deactivate” function, whereas on Windows there are separate scripts called deactivate.bat and Deactivate.ps1 which are installed when the virtual environment is created."

Way to reproduce under Windows 10, Python 3.6.4

1. Open elevated Powershell (Administrator access).
2. Activate virtual environment using Activate.ps1.
3. There is no Deactivate.ps1

Also, when the environment was activated with Activate.ps1, `deactivate` will not work. On the other hand, if the environment was activated simply with `activate` (it works) in Powershell, `deactivate` will also work.

Sorry, `deactivate` works in both cases `Scripts/Activate.ps1` and `Scripts/activate`. Only `Deactivate.ps1` is not created for the former, but the docs says that it should.

As noted in the related issue that you link to, there is not meant to be a deactivate.ps1 script - the deactivate command is provided via a global deactivate function created when you run activate.ps1 (although this is an implementation detail, all that matters is that a "deactivate" command exists, not how it is implemented).

The documentation of the implementation-specific behaviour is incorrect, but as it's describing internal implementation details, it shouldn't be relied on anyway.

Suggested documentation fix:

"""
You can deactivate a virtual environment by typing “deactivate” in your shell. The exact mechanism is platform-specific and is an internal implementation detail (typically a script of shell function will be used).
"""

As noted in the related issue that you link to, there is not meant to be a deactivate.ps1 script - the deactivate command is provided via a global deactivate function created when you run activate.ps1 (although this is an implementation detail, all that matters is that a "deactivate" command exists, not how it is implemented).

The documentation of the implementation-specific behaviour is incorrect, but as it's describing internal implementation details, it shouldn't be relied on anyway.

Suggested documentation fix:

"""
You can deactivate a virtual environment by typing “deactivate” in your shell. The exact mechanism is platform-specific and is an internal implementation detail (typically a script of shell function will be used).
"""

Yes, I agree, I did not understand the documentation correctly. It seems to me that the problem in the perception arose because of the fact that "deactivate" is not formatted as shell command, while `Deactivate.ps1` and others are. So I think simple formatting will be enough.

Also, it is not mentioned in the documentation that it is possible to activate environment in Powershell with "Drive:\> <venv>\Scripts\activate", but maybe it's not always true and I have nowhere to check.

New changeset 91e49575095ca16d1b67dd8822deeb7885e421da by Steve Dower (Derek Keeler) in branch 'master':
bpo-32910: Remove implementation detail in venv documentation. (GH-14968)
https://github.com/python/cpython/commit/91e49575095ca16d1b67dd8822deeb7885e421da

New changeset 4b6421c61e9335253ea7004f2878317b88096c30 by Miss Islington (bot) in branch '3.7':
bpo-32910: Remove implementation detail in venv documentation. (GH-14968)
https://github.com/python/cpython/commit/4b6421c61e9335253ea7004f2878317b88096c30

New changeset 06e8fc95d138775e942c18c8e47e72cdcc32f95c by Miss Islington (bot) in branch '3.8':
bpo-32910: Remove implementation detail in venv documentation. (GH-14968)
https://github.com/python/cpython/commit/06e8fc95d138775e942c18c8e47e72cdcc32f95c