{tidyr}
pivot data frame to be wider
{tidyr}
pivot data frame to be longer
{tidyr}
split single column into multiple columns
{tidyr}
expand data frame to include all possible combinations of values
{tidyr}
expand data frame to include combinations of values present in data
{tidyr}
complete a data frame with missing combinations of data
{tidyr}
combine multiple columns into single column
{dplyr}
combine vectors by returning the first non-missing value at each position
The end!