polars_core/series/implementations/
null.rs

1use std::any::Any;
2
3use polars_error::constants::LENGTH_LIMIT_MSG;
4
5use self::compare_inner::TotalOrdInner;
6use crate::prelude::compare_inner::{IntoTotalEqInner, TotalEqInner};
7use crate::prelude::*;
8use crate::series::private::{PrivateSeries, PrivateSeriesNumeric};
9use crate::series::*;
10
11impl Series {
12    pub fn new_null(name: PlSmallStr, len: usize) -> Series {
13        NullChunked::new(name, len).into_series()
14    }
15}
16
17#[derive(Clone)]
18pub struct NullChunked {
19    pub(crate) name: PlSmallStr,
20    length: IdxSize,
21    // we still need chunks as many series consumers expect
22    // chunks to be there
23    chunks: Vec<ArrayRef>,
24}
25
26impl NullChunked {
27    pub(crate) fn new(name: PlSmallStr, len: usize) -> Self {
28        Self {
29            name,
30            length: len as IdxSize,
31            chunks: vec![Box::new(arrow::array::NullArray::new(
32                ArrowDataType::Null,
33                len,
34            ))],
35        }
36    }
37}
38impl PrivateSeriesNumeric for NullChunked {
39    fn bit_repr(&self) -> Option<BitRepr> {
40        Some(BitRepr::Small(UInt32Chunked::full_null(
41            self.name.clone(),
42            self.len(),
43        )))
44    }
45}
46
47impl PrivateSeries for NullChunked {
48    fn compute_len(&mut self) {
49        fn inner(chunks: &[ArrayRef]) -> usize {
50            match chunks.len() {
51                // fast path
52                1 => chunks[0].len(),
53                _ => chunks.iter().fold(0, |acc, arr| acc + arr.len()),
54            }
55        }
56        self.length = IdxSize::try_from(inner(&self.chunks)).expect(LENGTH_LIMIT_MSG);
57    }
58    fn _field(&self) -> Cow<Field> {
59        Cow::Owned(Field::new(self.name().clone(), DataType::Null))
60    }
61
62    #[allow(unused)]
63    fn _set_flags(&mut self, flags: StatisticsFlags) {}
64
65    fn _dtype(&self) -> &DataType {
66        &DataType::Null
67    }
68
69    #[cfg(feature = "zip_with")]
70    fn zip_with_same_type(&self, mask: &BooleanChunked, other: &Series) -> PolarsResult<Series> {
71        let len = match (self.len(), mask.len(), other.len()) {
72            (a, b, c) if a == b && b == c => a,
73            (1, a, b) | (a, 1, b) | (a, b, 1) if a == b => a,
74            (a, 1, 1) | (1, a, 1) | (1, 1, a) => a,
75            (_, 0, _) => 0,
76            _ => {
77                polars_bail!(ShapeMismatch: "shapes of `self`, `mask` and `other` are not suitable for `zip_with` operation")
78            },
79        };
80
81        Ok(Self::new(self.name().clone(), len).into_series())
82    }
83
84    fn into_total_eq_inner<'a>(&'a self) -> Box<dyn TotalEqInner + 'a> {
85        IntoTotalEqInner::into_total_eq_inner(self)
86    }
87    fn into_total_ord_inner<'a>(&'a self) -> Box<dyn TotalOrdInner + 'a> {
88        invalid_operation_panic!(into_total_ord_inner, self)
89    }
90
91    fn subtract(&self, _rhs: &Series) -> PolarsResult<Series> {
92        null_arithmetic(self, _rhs, "subtract")
93    }
94
95    fn add_to(&self, _rhs: &Series) -> PolarsResult<Series> {
96        null_arithmetic(self, _rhs, "add_to")
97    }
98    fn multiply(&self, _rhs: &Series) -> PolarsResult<Series> {
99        null_arithmetic(self, _rhs, "multiply")
100    }
101    fn divide(&self, _rhs: &Series) -> PolarsResult<Series> {
102        null_arithmetic(self, _rhs, "divide")
103    }
104    fn remainder(&self, _rhs: &Series) -> PolarsResult<Series> {
105        null_arithmetic(self, _rhs, "remainder")
106    }
107
108    #[cfg(feature = "algorithm_group_by")]
109    fn group_tuples(&self, _multithreaded: bool, _sorted: bool) -> PolarsResult<GroupsType> {
110        Ok(if self.is_empty() {
111            GroupsType::default()
112        } else {
113            GroupsType::Slice {
114                groups: vec![[0, self.length]],
115                rolling: false,
116            }
117        })
118    }
119
120    #[cfg(feature = "algorithm_group_by")]
121    unsafe fn agg_list(&self, groups: &GroupsType) -> Series {
122        AggList::agg_list(self, groups)
123    }
124
125    fn _get_flags(&self) -> StatisticsFlags {
126        StatisticsFlags::empty()
127    }
128
129    fn vec_hash(&self, random_state: PlRandomState, buf: &mut Vec<u64>) -> PolarsResult<()> {
130        VecHash::vec_hash(self, random_state, buf)?;
131        Ok(())
132    }
133
134    fn vec_hash_combine(
135        &self,
136        build_hasher: PlRandomState,
137        hashes: &mut [u64],
138    ) -> PolarsResult<()> {
139        VecHash::vec_hash_combine(self, build_hasher, hashes)?;
140        Ok(())
141    }
142}
143
144fn null_arithmetic(lhs: &NullChunked, rhs: &Series, op: &str) -> PolarsResult<Series> {
145    let output_len = match (lhs.len(), rhs.len()) {
146        (1, len_r) => len_r,
147        (len_l, 1) => len_l,
148        (len_l, len_r) if len_l == len_r => len_l,
149        _ => polars_bail!(ComputeError: "Cannot {:?} two series of different lengths.", op),
150    };
151    Ok(NullChunked::new(lhs.name().clone(), output_len).into_series())
152}
153
154impl SeriesTrait for NullChunked {
155    fn name(&self) -> &PlSmallStr {
156        &self.name
157    }
158
159    fn rename(&mut self, name: PlSmallStr) {
160        self.name = name
161    }
162
163    fn chunks(&self) -> &Vec<ArrayRef> {
164        &self.chunks
165    }
166    unsafe fn chunks_mut(&mut self) -> &mut Vec<ArrayRef> {
167        &mut self.chunks
168    }
169
170    fn chunk_lengths(&self) -> ChunkLenIter {
171        self.chunks.iter().map(|chunk| chunk.len())
172    }
173
174    fn take(&self, indices: &IdxCa) -> PolarsResult<Series> {
175        Ok(NullChunked::new(self.name.clone(), indices.len()).into_series())
176    }
177
178    unsafe fn take_unchecked(&self, indices: &IdxCa) -> Series {
179        NullChunked::new(self.name.clone(), indices.len()).into_series()
180    }
181
182    fn take_slice(&self, indices: &[IdxSize]) -> PolarsResult<Series> {
183        Ok(NullChunked::new(self.name.clone(), indices.len()).into_series())
184    }
185
186    unsafe fn take_slice_unchecked(&self, indices: &[IdxSize]) -> Series {
187        NullChunked::new(self.name.clone(), indices.len()).into_series()
188    }
189
190    fn len(&self) -> usize {
191        self.length as usize
192    }
193
194    fn has_nulls(&self) -> bool {
195        self.len() > 0
196    }
197
198    fn rechunk(&self) -> Series {
199        NullChunked::new(self.name.clone(), self.len()).into_series()
200    }
201
202    fn drop_nulls(&self) -> Series {
203        NullChunked::new(self.name.clone(), 0).into_series()
204    }
205
206    fn cast(&self, dtype: &DataType, _cast_options: CastOptions) -> PolarsResult<Series> {
207        Ok(Series::full_null(self.name.clone(), self.len(), dtype))
208    }
209
210    fn null_count(&self) -> usize {
211        self.len()
212    }
213
214    #[cfg(feature = "algorithm_group_by")]
215    fn unique(&self) -> PolarsResult<Series> {
216        let ca = NullChunked::new(self.name.clone(), self.n_unique().unwrap());
217        Ok(ca.into_series())
218    }
219
220    #[cfg(feature = "algorithm_group_by")]
221    fn n_unique(&self) -> PolarsResult<usize> {
222        let n = if self.is_empty() { 0 } else { 1 };
223        Ok(n)
224    }
225
226    #[cfg(feature = "algorithm_group_by")]
227    fn arg_unique(&self) -> PolarsResult<IdxCa> {
228        let idxs: Vec<IdxSize> = (0..self.n_unique().unwrap() as IdxSize).collect();
229        Ok(IdxCa::new(self.name().clone(), idxs))
230    }
231
232    fn new_from_index(&self, _index: usize, length: usize) -> Series {
233        NullChunked::new(self.name.clone(), length).into_series()
234    }
235
236    unsafe fn get_unchecked(&self, _index: usize) -> AnyValue {
237        AnyValue::Null
238    }
239
240    fn slice(&self, offset: i64, length: usize) -> Series {
241        let (chunks, len) = chunkops::slice(&self.chunks, offset, length, self.len());
242        NullChunked {
243            name: self.name.clone(),
244            length: len as IdxSize,
245            chunks,
246        }
247        .into_series()
248    }
249
250    fn split_at(&self, offset: i64) -> (Series, Series) {
251        let (l, r) = chunkops::split_at(self.chunks(), offset, self.len());
252        (
253            NullChunked {
254                name: self.name.clone(),
255                length: l.iter().map(|arr| arr.len() as IdxSize).sum(),
256                chunks: l,
257            }
258            .into_series(),
259            NullChunked {
260                name: self.name.clone(),
261                length: r.iter().map(|arr| arr.len() as IdxSize).sum(),
262                chunks: r,
263            }
264            .into_series(),
265        )
266    }
267
268    fn sort_with(&self, _options: SortOptions) -> PolarsResult<Series> {
269        Ok(self.clone().into_series())
270    }
271
272    fn arg_sort(&self, _options: SortOptions) -> IdxCa {
273        IdxCa::from_vec(self.name().clone(), (0..self.len() as IdxSize).collect())
274    }
275
276    fn is_null(&self) -> BooleanChunked {
277        BooleanChunked::full(self.name().clone(), true, self.len())
278    }
279
280    fn is_not_null(&self) -> BooleanChunked {
281        BooleanChunked::full(self.name().clone(), false, self.len())
282    }
283
284    fn reverse(&self) -> Series {
285        self.clone().into_series()
286    }
287
288    fn filter(&self, filter: &BooleanChunked) -> PolarsResult<Series> {
289        let len = if self.is_empty() {
290            // We still allow a length of `1` because it could be `lit(true)`.
291            polars_ensure!(filter.len() <= 1, ShapeMismatch: "filter's length: {} differs from that of the series: 0", filter.len());
292            0
293        } else if filter.len() == 1 {
294            return match filter.get(0) {
295                Some(true) => Ok(self.clone().into_series()),
296                None | Some(false) => Ok(NullChunked::new(self.name.clone(), 0).into_series()),
297            };
298        } else {
299            polars_ensure!(filter.len() == self.len(), ShapeMismatch: "filter's length: {} differs from that of the series: {}", filter.len(), self.len());
300            filter.sum().unwrap_or(0) as usize
301        };
302        Ok(NullChunked::new(self.name.clone(), len).into_series())
303    }
304
305    fn shift(&self, _periods: i64) -> Series {
306        self.clone().into_series()
307    }
308
309    fn append(&mut self, other: &Series) -> PolarsResult<()> {
310        polars_ensure!(other.dtype() == &DataType::Null, ComputeError: "expected null dtype");
311        // we don't create a new null array to keep probability of aligned chunks higher
312        self.length += other.len() as IdxSize;
313        self.chunks.extend(other.chunks().iter().cloned());
314        Ok(())
315    }
316    fn append_owned(&mut self, mut other: Series) -> PolarsResult<()> {
317        polars_ensure!(other.dtype() == &DataType::Null, ComputeError: "expected null dtype");
318        // we don't create a new null array to keep probability of aligned chunks higher
319        let other: &mut NullChunked = other._get_inner_mut().as_any_mut().downcast_mut().unwrap();
320        self.length += other.len() as IdxSize;
321        self.chunks.extend(std::mem::take(&mut other.chunks));
322        Ok(())
323    }
324
325    fn extend(&mut self, other: &Series) -> PolarsResult<()> {
326        *self = NullChunked::new(self.name.clone(), self.len() + other.len());
327        Ok(())
328    }
329
330    fn clone_inner(&self) -> Arc<dyn SeriesTrait> {
331        Arc::new(self.clone())
332    }
333
334    fn as_any(&self) -> &dyn Any {
335        self
336    }
337
338    fn as_any_mut(&mut self) -> &mut dyn Any {
339        self
340    }
341
342    fn as_phys_any(&self) -> &dyn Any {
343        self
344    }
345
346    fn as_arc_any(self: Arc<Self>) -> Arc<dyn Any + Send + Sync> {
347        self as _
348    }
349}
350
351unsafe impl IntoSeries for NullChunked {
352    fn into_series(self) -> Series
353    where
354        Self: Sized,
355    {
356        Series(Arc::new(self))
357    }
358}
polars_core/series/implementations/null.rs

polars_core/series/implementations/
null.rs
