Thank you very much Kevin. P / max (1,p+c) , you mean put volume / the higher number btw put volume+ call volume and ???
No, the base formula would be P / (P+C) so that the number is a proportion between zero and one. The max(1,(P+C)) is so that you have a one in the denominator in the rare instances where both put and call volume is zero. In many languages 0 / 0 is +Inf or throws an error.
victsavio ORATS provides a data API for programmers and an Excel interface to access the data you mention plus much more. Put Call Ratios are there and also a measure of skew so you can see if there is pressure on the low strike puts or the high strike calls that may be moving the implied volatility relationships. You can see all the data headers in our docs: https://docs.orats.io/data-api-guide/definitions.html
Have you checked out Algoseek (https://www.algoseek.com/equity-options/)? I have worked with their Trade and Quotes data on US Equities before and I was pretty satisfied with it...