group_split: Split data.frame by groups

Description

group_split() works like base::split() but

it uses the grouping structure from group_by() and is therefore subject to the data mask
it does not name the elements of the list based on the grouping as this typically loses information and is confusing

Usage

group_split(.data, ..., .keep = TRUE)
group_keys(.data)

Value

group_split() returns a list of data.frames. Each data.frame contains the rows of .data with the associated group and all the columns, including the grouping variables.
group_keys() returns a data.frame with one row per group, and one column per grouping variable

Arguments

.data: A data.frame.
...: Grouping specification, forwarded to group_by().
.keep: logical(1). Should the grouping columns be kept (default: TRUE)?

Details

Grouped data.frames:

The primary use case for group_split() is with already groups data.frames, typically a result of group_by(). In this case, group_split() only uses the first argument, the grouped data.frame, and warns when ... is used.

Because some of these groups may be empty, it is best paired with group_keys() which identifies the representatives of each grouping variable for the group.

Ungrouped data.frames:

When used on ungrouped data.frames, group_split() forwards the ... to group_by() before the split, therefore the ... are subject to the data mask.

Examples

Run this code

# Grouped data.frames:
mtcars %>% group_by(cyl, am) %>% group_split()
mtcars %>% group_by(cyl, am) %>% group_split(.keep = FALSE)
mtcars %>% group_by(cyl, am) %>% group_keys()

# Ungrouped data.frames:
mtcars %>% group_split(am, cyl)