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 super::*;
7use crate::chunked_array::ops::compare_inner::{IntoTotalEqInner, NonNull, TotalEqInner};
8use crate::chunked_array::ops::sort::arg_sort_multiple::arg_sort_multiple_impl;
9use crate::series::private::{PrivateSeries, PrivateSeriesNumeric};
10use crate::series::*;
11
12impl Series {
13    pub fn new_null(name: PlSmallStr, len: usize) -> Series {
14        NullChunked::new(name, len).into_series()
15    }
16}
17
18#[derive(Clone)]
19pub struct NullChunked {
20    pub(crate) name: PlSmallStr,
21    length: usize,
22    // we still need chunks as many series consumers expect
23    // chunks to be there
24    chunks: Vec<ArrayRef>,
25}
26
27impl NullChunked {
28    pub(crate) fn new(name: PlSmallStr, len: usize) -> Self {
29        if len >= (IdxSize::MAX as usize) && chunkops::CHECK_LENGTH.get() {
30            panic!("{}", LENGTH_LIMIT_MSG);
31        }
32
33        Self {
34            name,
35            length: len,
36            chunks: vec![Box::new(arrow::array::NullArray::new(
37                ArrowDataType::Null,
38                len,
39            ))],
40        }
41    }
42
43    pub fn len(&self) -> usize {
44        self.length
45    }
46
47    pub fn is_empty(&self) -> bool {
48        self.length == 0
49    }
50}
51impl PrivateSeriesNumeric for NullChunked {
52    fn bit_repr(&self) -> Option<BitRepr> {
53        Some(BitRepr::U32(UInt32Chunked::full_null(
54            self.name.clone(),
55            self.len(),
56        )))
57    }
58}
59
60impl PrivateSeries for NullChunked {
61    fn compute_len(&mut self) {
62        fn inner(chunks: &[ArrayRef]) -> usize {
63            match chunks.len() {
64                // fast path
65                1 => chunks[0].len(),
66                _ => chunks.iter().fold(0, |acc, arr| acc + arr.len()),
67            }
68        }
69        let len = inner(&self.chunks);
70        if len >= (IdxSize::MAX as usize) && chunkops::CHECK_LENGTH.get() {
71            panic!("{}", LENGTH_LIMIT_MSG);
72        }
73        self.length = len;
74    }
75    fn _field(&self) -> Cow<'_, Field> {
76        Cow::Owned(Field::new(self.name().clone(), DataType::Null))
77    }
78
79    #[allow(unused)]
80    fn _set_flags(&mut self, flags: StatisticsFlags) {}
81
82    fn _dtype(&self) -> &DataType {
83        &DataType::Null
84    }
85
86    #[cfg(feature = "zip_with")]
87    fn zip_with_same_type(&self, mask: &BooleanChunked, other: &Series) -> PolarsResult<Series> {
88        let len = match (self.len(), mask.len(), other.len()) {
89            (a, b, c) if a == b && b == c => a,
90            (1, a, b) | (a, 1, b) | (a, b, 1) if a == b => a,
91            (a, 1, 1) | (1, a, 1) | (1, 1, a) => a,
92            (_, 0, _) => 0,
93            _ => {
94                polars_bail!(ShapeMismatch: "shapes of `self`, `mask` and `other` are not suitable for `zip_with` operation")
95            },
96        };
97
98        Ok(Self::new(self.name().clone(), len).into_series())
99    }
100
101    fn into_total_eq_inner<'a>(&'a self) -> Box<dyn TotalEqInner + 'a> {
102        IntoTotalEqInner::into_total_eq_inner(self)
103    }
104    fn into_total_ord_inner<'a>(&'a self) -> Box<dyn TotalOrdInner + 'a> {
105        IntoTotalOrdInner::into_total_ord_inner(self)
106    }
107
108    fn subtract(&self, _rhs: &Series) -> PolarsResult<Series> {
109        null_arithmetic(self, _rhs, "subtract")
110    }
111
112    fn add_to(&self, _rhs: &Series) -> PolarsResult<Series> {
113        null_arithmetic(self, _rhs, "add_to")
114    }
115    fn multiply(&self, _rhs: &Series) -> PolarsResult<Series> {
116        null_arithmetic(self, _rhs, "multiply")
117    }
118    fn divide(&self, _rhs: &Series) -> PolarsResult<Series> {
119        null_arithmetic(self, _rhs, "divide")
120    }
121    fn remainder(&self, _rhs: &Series) -> PolarsResult<Series> {
122        null_arithmetic(self, _rhs, "remainder")
123    }
124
125    #[cfg(feature = "algorithm_group_by")]
126    fn group_tuples(&self, _multithreaded: bool, _sorted: bool) -> PolarsResult<GroupsType> {
127        Ok(if self.is_empty() {
128            GroupsType::default()
129        } else {
130            GroupsType::new_slice(vec![[0, self.length as IdxSize]], false, true)
131        })
132    }
133
134    #[cfg(feature = "algorithm_group_by")]
135    unsafe fn agg_list(&self, groups: &GroupsType) -> Series {
136        AggList::agg_list(self, groups)
137    }
138
139    fn _get_flags(&self) -> StatisticsFlags {
140        StatisticsFlags::empty()
141    }
142
143    fn vec_hash(
144        &self,
145        random_state: PlSeedableRandomStateQuality,
146        buf: &mut Vec<u64>,
147    ) -> PolarsResult<()> {
148        VecHash::vec_hash(self, random_state, buf)?;
149        Ok(())
150    }
151
152    fn vec_hash_combine(
153        &self,
154        build_hasher: PlSeedableRandomStateQuality,
155        hashes: &mut [u64],
156    ) -> PolarsResult<()> {
157        VecHash::vec_hash_combine(self, build_hasher, hashes)?;
158        Ok(())
159    }
160
161    fn arg_sort_multiple(
162        &self,
163        by: &[Column],
164        options: &SortMultipleOptions,
165    ) -> PolarsResult<IdxCa> {
166        let vals = (0..self.len())
167            .map(|i| (i as IdxSize, NonNull(())))
168            .collect();
169        arg_sort_multiple_impl(vals, by, options)
170    }
171}
172
173fn null_arithmetic(lhs: &NullChunked, rhs: &Series, op: &str) -> PolarsResult<Series> {
174    let output_len = match (lhs.len(), rhs.len()) {
175        (1, len_r) => len_r,
176        (len_l, 1) => len_l,
177        (len_l, len_r) if len_l == len_r => len_l,
178        _ => polars_bail!(ComputeError: "Cannot {:?} two series of different lengths.", op),
179    };
180    Ok(NullChunked::new(lhs.name().clone(), output_len).into_series())
181}
182
183impl SeriesTrait for NullChunked {
184    fn name(&self) -> &PlSmallStr {
185        &self.name
186    }
187
188    fn rename(&mut self, name: PlSmallStr) {
189        self.name = name
190    }
191
192    fn chunks(&self) -> &Vec<ArrayRef> {
193        &self.chunks
194    }
195    unsafe fn chunks_mut(&mut self) -> &mut Vec<ArrayRef> {
196        &mut self.chunks
197    }
198
199    fn chunk_lengths(&self) -> ChunkLenIter<'_> {
200        self.chunks.iter().map(|chunk| chunk.len())
201    }
202
203    fn take(&self, indices: &IdxCa) -> PolarsResult<Series> {
204        Ok(NullChunked::new(self.name.clone(), indices.len()).into_series())
205    }
206
207    unsafe fn take_unchecked(&self, indices: &IdxCa) -> Series {
208        NullChunked::new(self.name.clone(), indices.len()).into_series()
209    }
210
211    fn take_slice(&self, indices: &[IdxSize]) -> PolarsResult<Series> {
212        Ok(NullChunked::new(self.name.clone(), indices.len()).into_series())
213    }
214
215    unsafe fn take_slice_unchecked(&self, indices: &[IdxSize]) -> Series {
216        NullChunked::new(self.name.clone(), indices.len()).into_series()
217    }
218
219    fn deposit(&self, validity: &Bitmap) -> Series {
220        assert_eq!(validity.set_bits(), 0);
221        self.clone().into_series()
222    }
223
224    fn len(&self) -> usize {
225        self.length
226    }
227
228    fn has_nulls(&self) -> bool {
229        !self.is_empty()
230    }
231
232    fn rechunk(&self) -> Series {
233        NullChunked::new(self.name.clone(), self.len()).into_series()
234    }
235
236    fn with_validity(&self, _validity: Option<Bitmap>) -> Series {
237        self.clone().into_series()
238    }
239
240    fn drop_nulls(&self) -> Series {
241        NullChunked::new(self.name.clone(), 0).into_series()
242    }
243
244    fn cast(&self, dtype: &DataType, _cast_options: CastOptions) -> PolarsResult<Series> {
245        Ok(Series::full_null(self.name.clone(), self.len(), dtype))
246    }
247
248    fn null_count(&self) -> usize {
249        self.len()
250    }
251
252    #[cfg(feature = "algorithm_group_by")]
253    fn unique(&self) -> PolarsResult<Series> {
254        let ca = NullChunked::new(self.name.clone(), self.n_unique().unwrap());
255        Ok(ca.into_series())
256    }
257
258    #[cfg(feature = "algorithm_group_by")]
259    fn n_unique(&self) -> PolarsResult<usize> {
260        let n = if self.is_empty() { 0 } else { 1 };
261        Ok(n)
262    }
263
264    #[cfg(feature = "algorithm_group_by")]
265    fn arg_unique(&self) -> PolarsResult<IdxCa> {
266        let idxs: Vec<IdxSize> = (0..self.n_unique().unwrap() as IdxSize).collect();
267        Ok(IdxCa::new(self.name().clone(), idxs))
268    }
269
270    #[cfg(feature = "algorithm_group_by")]
271    fn unique_id(&self) -> PolarsResult<(IdxSize, Vec<IdxSize>)> {
272        if self.is_empty() {
273            Ok((0, Vec::new()))
274        } else {
275            Ok((1, vec![0; self.len()]))
276        }
277    }
278
279    fn new_from_index(&self, _index: usize, length: usize) -> Series {
280        NullChunked::new(self.name.clone(), length).into_series()
281    }
282
283    unsafe fn get_unchecked(&self, _index: usize) -> AnyValue<'_> {
284        AnyValue::Null
285    }
286
287    fn slice(&self, offset: i64, length: usize) -> Series {
288        let (chunks, len) = chunkops::slice(&self.chunks, offset, length, self.len());
289        NullChunked {
290            name: self.name.clone(),
291            length: len,
292            chunks,
293        }
294        .into_series()
295    }
296
297    fn split_at(&self, offset: i64) -> (Series, Series) {
298        let (l, r) = chunkops::split_at(self.chunks(), offset, self.len());
299        (
300            NullChunked {
301                name: self.name.clone(),
302                length: l.iter().map(|arr| arr.len()).sum(),
303                chunks: l,
304            }
305            .into_series(),
306            NullChunked {
307                name: self.name.clone(),
308                length: r.iter().map(|arr| arr.len()).sum(),
309                chunks: r,
310            }
311            .into_series(),
312        )
313    }
314
315    fn sort_with(&self, _options: SortOptions) -> PolarsResult<Series> {
316        Ok(self.clone().into_series())
317    }
318
319    fn arg_sort(&self, _options: SortOptions) -> IdxCa {
320        IdxCa::from_vec(self.name().clone(), (0..self.len() as IdxSize).collect())
321    }
322
323    fn is_null(&self) -> BooleanChunked {
324        BooleanChunked::full(self.name().clone(), true, self.len())
325    }
326
327    fn is_not_null(&self) -> BooleanChunked {
328        BooleanChunked::full(self.name().clone(), false, self.len())
329    }
330
331    fn reverse(&self) -> Series {
332        self.clone().into_series()
333    }
334
335    fn filter(&self, filter: &BooleanChunked) -> PolarsResult<Series> {
336        let len = if self.is_empty() {
337            // We still allow a length of `1` because it could be `lit(true)`.
338            polars_ensure!(filter.len() <= 1, ShapeMismatch: "filter's length: {} differs from that of the series: 0", filter.len());
339            0
340        } else if filter.len() == 1 {
341            return match filter.get(0) {
342                Some(true) => Ok(self.clone().into_series()),
343                None | Some(false) => Ok(NullChunked::new(self.name.clone(), 0).into_series()),
344            };
345        } else {
346            polars_ensure!(filter.len() == self.len(), ShapeMismatch: "filter's length: {} differs from that of the series: {}", filter.len(), self.len());
347            filter.sum().unwrap_or(0) as usize
348        };
349        Ok(NullChunked::new(self.name.clone(), len).into_series())
350    }
351
352    fn shift(&self, _periods: i64) -> Series {
353        self.clone().into_series()
354    }
355
356    fn sum_reduce(&self) -> PolarsResult<Scalar> {
357        Ok(Scalar::null(DataType::Null))
358    }
359
360    fn min_reduce(&self) -> PolarsResult<Scalar> {
361        Ok(Scalar::null(DataType::Null))
362    }
363
364    fn max_reduce(&self) -> PolarsResult<Scalar> {
365        Ok(Scalar::null(DataType::Null))
366    }
367
368    fn mean_reduce(&self) -> PolarsResult<Scalar> {
369        Ok(Scalar::null(DataType::Null))
370    }
371
372    fn median_reduce(&self) -> PolarsResult<Scalar> {
373        Ok(Scalar::null(DataType::Null))
374    }
375
376    fn std_reduce(&self, _ddof: u8) -> PolarsResult<Scalar> {
377        Ok(Scalar::null(DataType::Null))
378    }
379
380    fn var_reduce(&self, _ddof: u8) -> PolarsResult<Scalar> {
381        Ok(Scalar::null(DataType::Null))
382    }
383
384    fn append(&mut self, other: &Series) -> PolarsResult<()> {
385        polars_ensure!(other.dtype() == &DataType::Null, ComputeError: "expected null dtype");
386        // we don't create a new null array to keep probability of aligned chunks higher
387        self.length += other.len();
388        self.chunks.extend(other.chunks().iter().cloned());
389        Ok(())
390    }
391    fn append_owned(&mut self, mut other: Series) -> PolarsResult<()> {
392        polars_ensure!(other.dtype() == &DataType::Null, ComputeError: "expected null dtype");
393        // we don't create a new null array to keep probability of aligned chunks higher
394        let other: &mut NullChunked = other._get_inner_mut().as_any_mut().downcast_mut().unwrap();
395        self.length += other.len();
396        self.chunks.extend(std::mem::take(&mut other.chunks));
397        Ok(())
398    }
399
400    fn extend(&mut self, other: &Series) -> PolarsResult<()> {
401        *self = NullChunked::new(self.name.clone(), self.len() + other.len());
402        Ok(())
403    }
404
405    #[cfg(feature = "approx_unique")]
406    fn approx_n_unique(&self) -> PolarsResult<IdxSize> {
407        Ok(if self.is_empty() { 0 } else { 1 })
408    }
409
410    fn clone_inner(&self) -> Arc<dyn SeriesTrait> {
411        Arc::new(self.clone())
412    }
413
414    fn find_validity_mismatch(&self, other: &Series, idxs: &mut Vec<IdxSize>) {
415        ChunkNestingUtils::find_validity_mismatch(self, other, idxs)
416    }
417
418    fn as_any(&self) -> &dyn Any {
419        self
420    }
421
422    fn as_any_mut(&mut self) -> &mut dyn Any {
423        self
424    }
425
426    fn as_phys_any(&self) -> &dyn Any {
427        self
428    }
429
430    fn as_arc_any(self: Arc<Self>) -> Arc<dyn Any + Send + Sync> {
431        self as _
432    }
433}
434
435unsafe impl IntoSeries for NullChunked {
436    fn into_series(self) -> Series
437    where
438        Self: Sized,
439    {
440        Series(Arc::new(self))
441    }
442}
polars_core/series/implementations/null.rs

polars_core/series/implementations/
null.rs
