datatable.union()¶
Find the union of values in all frames
.
Each frame should have only a single column or be empty. The values in each frame will be treated as a set, and this function will perform the union operation on these sets.
The dt.union(*frames)
operation is equivalent to
dt.unique(dt.rbind(*frames))
.
Parameters¶
Frame
| Frame
| ...
Input single-column frames.
Frame
A single-column frame. The column stype is the smallest common
stype of columns in the frames
.
ValueError
| NotImplementedError
raised when one of the input frames has more than one column. |
|
raised when one of the columns has stype |
Examples¶
from datatable import dt
df = dt.Frame({'A': [1, 1, 2, 1, 2],
'B': [None, 2, 3, 4, 5],
'C': [1, 2, 1, 1, 2]})
df
A | B | C | ||
---|---|---|---|---|
int32 | int32 | int32 | ||
0 | 1 | NA | 1 | |
1 | 1 | 2 | 2 | |
2 | 2 | 3 | 1 | |
3 | 1 | 4 | 1 | |
4 | 2 | 5 | 2 |
Union of all the columns in a frame:
dt.union(*df)
A | ||
---|---|---|
int32 | ||
0 | NA | |
1 | 1 | |
2 | 2 | |
3 | 3 | |
4 | 4 | |
5 | 5 |
Union of two frames:
dt.union(df["A"], df["C"])
A | ||
---|---|---|
int32 | ||
0 | 1 | |
1 | 2 |
See Also¶
intersect()
– calculate the set intersection of values in the frames.setdiff()
– calculate the set difference between the frames.symdiff()
– calculate the symmetric difference between the sets of values in the frames.unique()
– find unique values in a frame.