Bug: ASCII range mentioned as U+0001..U+007F, rather than U+0000..U+007F

[ezequiel-garzon]

Describe the bug

Section 2.3. Identifiers and keywords of the python.org language reference indicates:

Within the ASCII range (U+0001..U+007F), the valid characters for identifiers include the uppercase and lowercase letters A through Z, the underscore _ and, except for the first character, the digits 0 through 9.

But the ASCII range is U+0000..U+007F, not U+0001..U+007F. The documentation points to PEP 3131, where the same range is used.

To Reproduce

Visit the referenced webpage.

Expected behavior

Unicode's first block, with "Range: 0000..007F" (second line of U0000), is known as Basic Latin or C0 Controls and Basic Latin. The official charts index page refers to it as Basic Latin (ASCII), emphasizing the historical connection with the older standard.

Therefore, if it is deemed necessary to clarify the ASCII range at all, it should be U+0000..U+007F, not U+0001..U+007F.

URL to the issue

https://docs.python.org/3/reference/lexical_analysis.html#identifiers

Screenshots

No response

Browsers

Chrome

Operating System

macOS

Browser Version

No response

Relevant log output

No response

Additional context

No response

[merwok]

Hello, this tracker is about the Python website, not the Python docs which are maintained with the CPython code at https://github.com/python/cpython

You can report the issue there.

[StanFromIreland]

I see arguments for both, since the null character would not be valid, and that is probably what the note in the PEP implied. Changing the docs should be fine, but this issue could simply fall under the existing meta issue: #135676. cc @encukou

[encukou]

NUL is not a valid source character, so the ASCII range for Python source code is indeed U+0001..U+007F.

I have a WIP branch that'll define “source character” for #135676, so I'll assign this to myself.

[terryjreedy]

>>> ord('\0')
0
>>> '\0'.isascii()
True 
>>> # But ...
>>> print(0, '\0', 0)
0 0  # In IDLE, that is \0 NUL between the 0s, but Firefox will not paste it.
>>> for c in '0 0': pass  # 3 chars copied from line above (but NUL not pasted).
SyntaxError: source code string cannot contain null bytes