how to read a syntax diagram

Sun May 27 19:24:57 EDT 2018

On 2018年5月27日 21:17:57 +0000, Paul wrote:
> hi,
> I'm using the Google Sheets API (the client library rather than the
> RESTful interface) and I'm confused about the meaning of the syntax
> diagrams.

*Diagrams*? As in, *pictures*?
> update(spreadsheetId=*, range=*, body=*, valueInputOption=None,
> x__xgafv=None, responseValueRenderOption=None,
> includeValuesInResponse=None, responseDateTimeRenderOption=None)
[...]
> My specific questions are:
> 1) is this standard (python?) syntax notation? I haven't found a key
> to this form of documentation.

No.
> 1) What does '=*' mean?

No idea.
> 2) What does '=None' mean? [my guess is that this means "no
> default value"].

If they are using the same meaning as the standard convention in Python, 
it means the opposite: that None is the default.
If they mean something else, your guess is as good as mine.
> 3) Note that it says that range is required. Through trial, I see
> that
> *one* of the 'range' specifications is required. I.E., I can specify
> 'range' outside body, or 'range' as part of body, or both, but I must
> have 'range' someplace. This is a bit confusing to me ( as opposed to
> my usual understanding of "required"). Also, what does range mean, in
> these two different spots, and what does it mean if two different values
> of range are specified?

No idea.
-- 
Steven D'Aprano
"Ever since I learned about confirmation bias, I've been seeing
it everywhere." -- Jon Ronson