vscode-python: "Run Selection" does not handle decorators properly.

def my_decorator(func):
    def wrapper():
        print("Something is happening before the function is called.")
        func()
        print("Something is happening after the function is called.")
    return wrapper


@my_decorator
def say_whee():
    print("Whee!")


say_whee()

shift+enter or ‘run’ button in vscode

>>> def my_decorator(func):
...     def wrapper():
...         print("Something is happening before the function is called.")
...         func()
...         print("Something is happening after the function is called.")
...     return wrapper
... @my_decorator
  File "<stdin>", line 7
    @my_decorator
    ^
SyntaxError: invalid syntax
>>>
>>> def say_whee():
...     print("Whee!")
...
>>> say_whee()
Whee!
>>>

python extension v2021.1.442908725-dev

About this issue

Original URL
State: closed
Created 4 years ago
Reactions: 12
Comments: 24 (7 by maintainers)

Most upvoted comments

Verification steps:

Download the latest Insiders version of the Python extension
Copy the code from the original message:

def my_decorator(func):
    def wrapper():
        print("Something is happening before the function is called.")
        func()
        print("Something is happening after the function is called.")
    return wrapper


@my_decorator
def say_whee():
    print("Whee!")


say_whee()

Select it all and press shift + enter or run the Run Selection/Line in Terminal command
Make sure that the code is passed to the terminal and executed without any errors

kimadeline on Nov 29, 2021

What appears to be happening is the following:

the decorator gets executed as a single line in isolation, which produces a syntax error.
the undecorated/plain python statement beneath the decorator gets executed in isolation.

Ways of executing code with decorators that do seem to be working normally are:

Copying an pasting code into the REPL
Executing the file from the command line using python [script-path]
Using “Python: Run Selection/Line in Python Terminal” (shift + enter) if the decorator is indented as part of some scope (e.g. within an if statement or within a class definition)

Hence it is only the top level decorators that don’t work with “Python: Run Selection/Line in Python Terminal” (shift + enter) and it seems to be because the lines get evaluated / executed in isolation if they are not part of some indented block or pasted in as a whole. If “Python: Run Selection/Line in Python Terminal” (shift + enter) could be made to work like pasting from the clipboard works, then the problem would be solved.

JordyScript on May 14, 2021