datatable.FExpr.__add__()

Add two FExprs together, which corresponds to python operator +.

If x or y are multi-column expressions, then they must have the same number of columns, and the + operator will be applied to each corresponding pair of columns. If either x or y are single-column while the other is multi-column, then the single-column expression will be repeated to the same number of columns as its opponent.

The result of adding two columns with different stypes will have the following stype:

  • max(x.stype, y.stype, int32) if both columns are numeric (i.e. bool, int or float);

  • str32/str64 if at least one of the columns is a string. In this case the + operator implements string concatenation, same as in Python.

Parameters

x
,
y
FExpr

The arguments must be either FExprs, or expressions that can be converted into FExprs.

return
FExpr

An expression that evaluates x + y.