[datar][ INFO] summarise() has grouped output by ['sale'l] (override with _groups argument)

[antonio-yu]

When will this warning message show?
When coding like this , the warning shows.
data >> groupy_by(f.col1) >> summarize(sum = f.col2.sum())

[pwwang]

Here explains it: https://dplyr.tidyverse.org/reference/summarise.html

.groups
[Experimental] Grouping structure of the result.

• "drop_last": dropping the last level of grouping. This was the only supported option before version 1.0.0.
• "drop": All levels of grouping are dropped.
• "keep": Same grouping structure as .data.
• "rowwise": Each row is its own group.

When .groups is not specified, it is chosen based on the number of rows of the results:

• If all the results have 1 row, you get "drop_last".
• If the number of rows varies, you get "keep".
  In addition, a message informs you of that choice, unless the result is ungrouped, the option "dplyr.summarise.inform" is set to FALSE, or when summarise() is called from a function in a package.

.groups corresponds to _groups argument in datar. You can use options(dplyr_summarise_inform=False) to always disable the message.

See also:

• https://stackoverflow.com/questions/62140483/how-to-interpret-dplyr-message-summarise-regrouping-output-by-x-override
• remove excessive groupby warnings from summarise() tidyverse/dplyr#5852