datatable.unique()¶
Find the unique values in all the columns of the frame
.
This function sorts the values in order to find the uniques, so the return values will be ordered. However, this should be considered an implementation detail: in the future datatable may switch to a different algorithm, such as hash-based, which may return the results in a different order.
Parameters¶
Frame
Input frame.
NotImplementedError
The exception is raised when one of the frame columns has stype obj64
.
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 |
Unique values in the entire frame:
dt.unique(df)
C0 | ||
---|---|---|
int32 | ||
0 | NA | |
1 | 1 | |
2 | 2 | |
3 | 3 | |
4 | 4 | |
5 | 5 |
Unique values in a frame with a single column:
dt.unique(df["A"])
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.union()
– calculate the union of values in the frames.