python · bebound · Aug 9, 2024 · Aug 28, 2024 · Sep 10, 2024 · iritkatriel
diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst
@@ -866,6 +866,8 @@ The following exceptions are used as warning categories; see the
 
    Base class for warnings about dubious syntax.
 
+   This warning is emitted when compiling Python source code to bytecode.
+
 
 .. exception:: RuntimeWarning
 

diff --git a/Doc/library/warnings.rst b/Doc/library/warnings.rst
@@ -80,7 +80,8 @@ The following warnings category classes are currently defined:
 |                                  | unless triggered by code in ``__main__``).    |
 +----------------------------------+-----------------------------------------------+
 | :exc:`SyntaxWarning`             | Base category for warnings about dubious      |
-|                                  | syntactic features.                           |
+|                                  | syntactic features (emitted when compiling    |
+|                                  | Python source code to bytecode).              |
 +----------------------------------+-----------------------------------------------+
 | :exc:`RuntimeWarning`            | Base category for warnings about dubious      |
 |                                  | runtime features.                             |
Original file line number	Diff line number	Diff line change
Expand Up		@@ -866,6 +866,8 @@ The following exceptions are used as warning categories; see the

		Base class for warnings about dubious syntax.

		This warning is emitted when compiling Python source code to bytecode.
Copy link Member iritkatriel Sep 12, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. I think this is too strong - we probably don't want to commit to only using this exception type in the compilation process. You can write an application that raises these exceptions if you want. Copy link Author bebound Sep 13, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. How about this? By default, the Python interpreter emits the `SyntaxWarning` during bytecode compilation. Copy link Member iritkatriel Sep 13, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. That's not in the language spec either. Copy link Author bebound Sep 13, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. I can't find a suitable word to describe the current behavior. Copy link Member iritkatriel Sep 13, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. That's the thing, we don't document "current behaviour". We document what we guarantee will not change without a deprecation process. The point of your PR is to alert people that compilation errors don't show up when the code is not being compiled. This may be worth mentioning in one of the tutorials (I'm not sure which), but I don't think the SyntaxError documentation is the right place for this. Copy link Author bebound Sep 14, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. I understand your concern that this document introduces some unofficially committed behavior for SyntaxWarning. I'm okay with leaving it here and waiting for more comments. I searched the repository and found the following: SyntaxWarning are only emitted once, and only when a Python file is parsed: when a cached PYC file is used, not warning is emitted -------#99011 (comment) The problem is the warnings are only shown once, when the file is compiled. Things would probably be improved if the warnings were always shown, as at least then devs will see the error once (although most will probably be confused when the warning doesn't repeat). --#77093 (comment)


		.. exception:: RuntimeWarning

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