Incorrectly reports an "= " inside a f-string as 'unexpected token'

[fbidu]

Hello! I just noticed that Pylance accepts f-strings with an equal sign at the end such as

print(f"{10 + 20 =}")

But it will complain with "invalid token" if a space is added after the = sign. I found this out while refactoring a test today:

Environment data

• Language Server version: 2020.7.3
• OS and version: Fedora 32
• Python version (& distribution if applicable, e.g. Anaconda): Python 3.8.3

Expected behaviour

Pylance should identify the space after an = sign as a valid token

Actual behaviour

It actually complains about the space

Logs

Python output logs as soon as I add the space and save:

> ~/.cache/pypoetry/virtualenvs/api-esther-AOXcjWyB-py3.8/bin/python ~/.vscode/extensions/ms-python.python-2020.7.96456/pythonFiles/pyvsc-run-isolated.py pylint --msg-template='{line},{column},{category},{symbol}:{msg}' --reports=n --output-format=text ~/dev/faculdade/api_esther/tests/api/test_help_asking.py
cwd: ~/dev/faculdade/api_esther
> ~/.cache/pypoetry/virtualenvs/api-esther-AOXcjWyB-py3.8/bin/python ~/.vscode/extensions/ms-python.python-2020.7.96456/pythonFiles/pyvsc-run-isolated.py pylint --msg-template='{line},{column},{category},{symbol}:{msg}' --reports=n --output-format=text ~/dev/faculdade/api_esther/tests/api/test_help_asking.py
cwd: ~/dev/faculdade/api_esther
> ~/.cache/pypoetry/virtualenvs/api-esther-AOXcjWyB-py3.8/bin/python ~/.vscode/extensions/ms-python.python-2020.7.96456/pythonFiles/testing_tools/run_adapter.py discover pytest -- --rootdir ~/dev/faculdade/api_esther -s --cache-clear tests
cwd: ~/dev/faculdade/api_esther
##########Linting Output - pylint##########

--------------------------------------------------------------------
Your code has been rated at 10.00/10 (previous run: 10.00/10, +0.00)

Code Snippet / Additional information

print(f"{10 + 20 = }")

[m1waterman88]

I came here to file an issue for this as well. PyLance is fine with f"{t1=}" and f"{t1 =}". It does not like a space after the equals sign: f"{t1= }" or f"{t1 = }".

Environment:
Pop!_OS 20.04

[erictraut]

Thanks for the bug report. This will be fixed in the next version of Pylance.

[jakebailey]

This issue has been fixed in version 2020.7.4, which we've just released. You can find the changelog here: https://github.com/microsoft/pylance-release/blob/master/CHANGELOG.md#202074-29-july-2020