May 19, 2025 · May 17, 2025 · May 17, 2025 · May 17, 2025 · May 19, 2025
diff --git a/Lib/_pyrepl/utils.py b/Lib/_pyrepl/utils.py

    @classmethod
    def from_token(cls, token: TI, line_len: list[int]) -> Self:
        end_offset = 0
        if ((token.type is T.FSTRING_MIDDLE or token.type is T.TSTRING_MIDDLE)
            and token.string.endswith(("{", "}"))):
            # Double braces in f-string / t-string are translated into a single
            # brace by the tokenizer, and are always at the end of the token:
            # we must add 1 to the token end position to color the two braces.
            end_offset = 1

        return cls(
            line_len[token.start[0] - 1] + token.start[1],
            line_len[token.end[0] - 1] + token.end[1] - 1,
            line_len[token.end[0] - 1] + token.end[1] - 1 + end_offset,
        )


diff --git a/Lib/test/test_pyrepl/test_reader.py b/Lib/test/test_pyrepl/test_reader.py
        self.assert_screen_equal(reader, code, clean=True)
        self.assert_screen_equal(reader, expected)

    def test_syntax_highlighting_literal_brace_in_fstring_or_tstring(self):
        code = dedent(
            """\
            f"{{"
            f"}}"
            f"a{{b"
            f"a}}b"
            f"a{{b}}c"
            t"a{{b}}c"
            f"{{{0}}}"
            f"{ {0} }"
            """
        )
        expected = dedent(
            """\
            {s}f"{z}{s}<<{z}{s}"{z}
            {s}f"{z}{s}>>{z}{s}"{z}
            {s}f"{z}{s}a<<{z}{s}b{z}{s}"{z}
            {s}f"{z}{s}a>>{z}{s}b{z}{s}"{z}
            {s}f"{z}{s}a<<{z}{s}b>>{z}{s}c{z}{s}"{z}
            {s}t"{z}{s}a<<{z}{s}b>>{z}{s}c{z}{s}"{z}
            {s}f"{z}{s}<<{z}{o}<{z}{n}0{z}{o}>{z}{s}>>{z}{s}"{z}
            {s}f"{z}{o}<{z} {o}<{z}{n}0{z}{o}>{z} {o}>{z}{s}"{z}
            """
        ).format(**colors).replace("<", "{").replace(">", "}")
        events = code_to_events(code)
        reader, _ = handle_all_events(events)
        self.assert_screen_equal(reader, code, clean=True)
        self.maxDiff=None
        self.assert_screen_equal(reader, expected)

    def test_control_characters(self):
        code = 'flag = "🏳️‍🌈"'
        events = code_to_events(code)
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-05-17-20-44-51.gh-issue-134158.ewLNLp.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-05-17-20-44-51.gh-issue-134158.ewLNLp.rst
 Fix PyREPL coloring of double braces in f-strings and t-strings
Original file line number	Diff line number	Diff line change
Expand Up		@@ -41,9 +41,17 @@ def from_re(cls, m: Match[str], group: int \| str) -> Self:

		@classmethod
		def from_token(cls, token: TI, line_len: list[int]) -> Self:
		end_offset = 0
		if ((token.type is T.FSTRING_MIDDLE or token.type is T.TSTRING_MIDDLE)
		and token.string.endswith(("{", "}"))):
		# Double braces in f-string / t-string are translated into a single
		# brace by the tokenizer, and are always at the end of the token:
		# we must add 1 to the token end position to color the two braces.
		end_offset = 1

		return cls(
		line_len[token.start[0] - 1] + token.start[1],
		line_len[token.end[0] - 1] + token.end[1] - 1,
		line_len[token.end[0] - 1] + token.end[1] - 1 + end_offset,
		)


Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -517,6 +517,37 @@ def unfinished_function():
		self.assert_screen_equal(reader, code, clean=True)
		self.assert_screen_equal(reader, expected)

		def test_syntax_highlighting_literal_brace_in_fstring_or_tstring(self):
		code = dedent(
		"""\
		f"{{"
		f"}}"
		f"a{{b"
		f"a}}b"
		f"a{{b}}c"
		t"a{{b}}c"
		f"{{{0}}}"
		f"{ {0} }"
		"""
		)
		expected = dedent(
		"""\
		{s}f"{z}{s}<<{z}{s}"{z}
		{s}f"{z}{s}>>{z}{s}"{z}
		{s}f"{z}{s}a<<{z}{s}b{z}{s}"{z}
		{s}f"{z}{s}a>>{z}{s}b{z}{s}"{z}
		{s}f"{z}{s}a<<{z}{s}b>>{z}{s}c{z}{s}"{z}
		{s}t"{z}{s}a<<{z}{s}b>>{z}{s}c{z}{s}"{z}
		{s}f"{z}{s}<<{z}{o}<{z}{n}0{z}{o}>{z}{s}>>{z}{s}"{z}
		{s}f"{z}{o}<{z} {o}<{z}{n}0{z}{o}>{z} {o}>{z}{s}"{z}
		"""
		).format(**colors).replace("<", "{").replace(">", "}")
		events = code_to_events(code)
		reader, _ = handle_all_events(events)
		self.assert_screen_equal(reader, code, clean=True)
		self.maxDiff=None
		self.assert_screen_equal(reader, expected)

		def test_control_characters(self):
		code = 'flag = "🏳️‍🌈"'
		events = code_to_events(code)
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Fix PyREPL coloring of double braces in f-strings and t-strings
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