polars Module prelude Copy item path Source _csv_read_internal polars-io_internal polars-ioaggregations arity array polars-ops and dtype-arraybinary lazybuffer polars-iobyte_source polars-io and cloudcat lazy and dtype-categoricalchunkedarray temporalTraits and utilities for temporal data. cloud polars-ioInterface with cloud storage through the object_store crate. compression polars-ioconcat_arr polars-ops and dtype-arraydatatypes Data types supported by Polars. datetime polars-ops and timezonesdefault_arrays dt lazy and temporalexpr file polars-iofill_null fixed_size_list dtype-arrayfloat_sorted_arg_max full function_expr lazygather interpolate polars-ops and interpolateinterpolate_by polars-ops and interpolate_bymode polars-ops and modenan_propagating_aggregate polars-ops and propagate_nansnull replace temporal and (dtype-date or dtype-datetime)row_encode schema_inference polars-iosearch_sorted series temporalsort strings polars-opsudf lazyutf8 zip zip_withdf polars_bail polars_ensure polars_err polars_warn AnonymousScanArgs lazyAnonymousScanOptions lazyArc A thread-safe reference-counting pointer. ‘Arc’ stands for ‘Atomically
Reference Counted’. ArrayNameSpace lazySpecialized expressions for SeriesDataType::Array ArrowField Represents Arrow’s metadata of a “column”. AsOfOptions polars-opsBatchedCsvReader polars-ioBatchedParquetReader polars-ioBinaryOffsetType BinaryType BooleanChunkedBuilder BooleanType Bounds temporalBoundsIter temporalBrotliLevel polars-ioA valid Brotli compression level. CatIter CategoricalChunked CategoricalChunkedBuilder CategoricalNameSpace lazySpecialized expressions for Categorical dtypes. CategoricalType ChainedThen lazyUtility struct for the when-then-otherwise expression. ChainedWhen lazyUtility struct for the when-then-otherwise expression. ChunkId ChunkedArray ChunkedArray CompatLevel CrossJoinOptions polars-opsCsvParseOptions polars-ioCsvReadOptions polars-ioCsvReader polars-ioCreate a new DataFrame by reading a csv file. CsvWriter polars-ioWrite a DataFrame to csv. CsvWriterOptions polars-ioOptions for writing CSV files. DataFrame A contiguous growable collection of Series that have the same length. DateType DatetimeArgs lazyArguments used by datetime in order to produce an Expr DatetimeType DecimalType Dimension Duration lazyDurationArgs lazyArguments used by duration in order to produce an ExprDuration DurationType DynamicGroupOptions lazyExprNameNameSpace lazySpecialized expressions for modifying the name of existing expressions. FalseT Field Characterizes the name and the DataType FieldsMapper lazyFileMetadata polars-ioMetadata for a Parquet file. FixedSizeListType dtype-arrayFloat32Type Float64Type GlobalRevMapMerger GroupBy Returned by a group_by operation on a DataFrame. This struct supports
several aggregations. GroupPositions GroupsIdx Indexes of the groups, the first index is stored separately.
this make sorting fast. GroupsTypeIter GroupsTypeParIter GzipLevel polars-ioA valid Gzip compression level. IEJoinOptions polars-opsInProcessQuery lazyInt8Type Int16Type Int32Type Int64Type Int128Type IpcReadOptions polars-ioIpcReader polars-ioRead Arrows IPC format into a DataFrame IpcReaderAsync polars-ioAn Arrow IPC reader implemented on top of PolarsObjectStore. IpcScanOptions polars-ioIpcStreamReader polars-ioRead Arrows Stream IPC format into a DataFrame IpcStreamWriter polars-ioWrite a DataFrame to Arrow’s Streaming IPC format IpcStreamWriterOption polars-ioIpcWriter polars-ioWrite a DataFrame to Arrow’s IPC format IpcWriterOptions polars-ioJoinArgs lazyJoinBuilder lazyJoinOptions lazyJsonLineReader polars-ioJsonReader polars-ioReads JSON in one of the formats in JsonFormat JsonWriter polars-ioWrites a DataFrame to JSON. JsonWriterOptions polars-ioLazyCsvReader lazy and csvLazyFrame lazyLazy abstraction over an eager DataFrame. LazyGroupBy lazyUtility struct for lazy group_by operation. LazyJsonLineReader lazyListBinaryChunkedBuilder ListBooleanChunkedBuilder ListNameSpace lazySpecialized expressions for SeriesDataType::List ListPrimitiveChunkedBuilder ListStringChunkedBuilder ListType Logical Maps a logical type to a chunked array implementation of the physical type.
This saves a lot of compiler bloat and allows us to reuse functionality. NoNull Just a wrapper structure which is useful for certain impl specializations. Null lazyThe literal Null NullableIdxSize ObjectType objectOptFlags lazyAllowed optimizations. OwnedBatchedCsvReader polars-ioOwnedObject objectParquetAsyncReader polars-io and cloudA Parquet reader on top of the async object_store API. Only the batch reader is implemented since
parquet files on cloud storage tend to be big and slow to access. ParquetOptions polars-ioParquetReader polars-ioRead Apache parquet format into a DataFrame. ParquetWriteOptions polars-ioParquetWriter polars-ioWrite a DataFrame to Parquet format. PlSmallStr String type that inlines small strings. PrimitiveChunkedBuilder RankOptions lazyRollingCovOptions lazyRollingGroupOptions lazyRollingOptionsDynamicWindow temporalRollingOptionsFixedWindow RollingQuantileParams RollingVarParams Scalar ScanArgsAnonymous lazyScanArgsIpc lazyScanArgsParquet lazySerializeOptions polars-ioOptions to serialize logical types to CSV. Series Series SortMultipleOptions Sort options for multi-series sorting. SortOptions Options for single series sorting. SpecialEq lazyWrapper type that has special equality properties
depending on the inner type specialization SplitNChars polars-opsStatisticsOptions polars-ioThe statistics to write StringCacheHolder Enable the global string cache as long as the object is alive (RAII ). StringType StrptimeOptions lazyStructArray polars-ioA StructArrayArrayArray StructNameSpace lazySpecialized expressions for Struct dtypes. StructType dtype-structThen lazyUtility struct for the when-then-otherwise expression. TimeType TrueT UInt8Type UInt16Type UInt32Type UInt64Type UnionArgs lazyUnpivotArgsDSL lazyUnpivotArgsIR Arguments for LazyFrame::unpivot function UserDefinedFunction lazyRepresents a user-defined function When lazyUtility struct for the when-then-otherwise expression. Window temporalRepresents a window in time ZstdLevel polars-ioA valid Zstandard compression level. AggExpr lazyAmbiguous AnyValue ArrowDataType The set of supported logical types in this crate. ArrowTimeUnit The time units defined in Arrow. AsofStrategy polars-opsBooleanFunction lazyCategoricalFunction lazyCategoricalOrdering ClosedInterval polars-opsClosedWindow temporalColumn A column within a DataFrame CommentPrefix polars-ioCsvEncoding polars-ioDataType DslPlan lazyExcluded lazyExpr lazyExpressions that can be used in various contexts. FillNullStrategy FunctionExpr lazyGroupByMethod GroupsIndicator GroupsType IndexOrder InequalityOperator polars-opsInterpolationMethod polars-opsIpcCompression polars-ioCompression codec JoinCoalesce polars-opsJoinType lazyJoinTypeOptions polars-opsJoinTypeOptionsIR lazyJoinValidation lazyJsonFormat polars-ioThe format to use to write the DataFrame to JSON: Json (a JSON array)
or JsonLines (each row output on a separate line). Label temporalLazySerde lazyLiteralValue lazyMaintainOrderJoin polars-opsNestedType lazyNonExistent NullStrategy polars-opsNullValues polars-ioOperator lazyParallelStrategy polars-ioParquetCompression polars-ioThe compression strategy to use for writing Parquet files. ParquetStatistics polars-ioParquet statistics for a nesting level PolarsError PowFunction lazyQuantileMethod QuoteStyle polars-ioQuote style indicating when to insert quotes around a field. RankMethod lazyReshapeDimension A dimension in a reshape. RevMapping RollingFnParams SearchSortedSide polars-opsSelector lazyStartBy temporalStringFunction lazyStructFunction lazyTemporalFunction lazyTimeUnit UniqueKeepStrategy UnknownKind WindowMapping lazyWindowType lazyIDX_DTYPE Non-bigidx NULL lazyURL_ENCODE_CHAR_SET polars-ioBOOLEAN_RE polars-ioEXTENSION_NAME FLOAT_RE polars-ioFLOAT_RE_DECIMAL polars-ioINTEGER_RE polars-ioPOLARS_TEMP_DIR_BASE_PATH polars-ioAnonymousScan lazyArgAgg polars-opsArgmin/ Argmax ArithmeticChunked ArrayCollectIterExt ArrayFromIter ArrayFromIterDtype AsBinary polars-opsAsList polars-opsAsRefDataType AsString polars-opsAsofJoin polars-opsAsofJoinBy polars-opsBinaryNameSpaceImpl polars-opsBinaryUdfOutputField lazyCategoricalMergeOperation ChunkAgg Aggregation operations. ChunkAggSeries Aggregations that return Series ChunkAnyValue ChunkApply Fastest way to do elementwise operations on a ChunkedArray<T> ChunkApplyKernel Apply kernels on the arrow array chunks in a ChunkedArray. ChunkApproxNUnique approx_uniqueChunkBytes ChunkCast Cast ChunkedArray<T> to ChunkedArray<N> ChunkCompareEq Compare SeriesChunkedArrayboolean mask that
can be used to filter rows. ChunkCompareIneq Compare SeriesChunkedArray<, >=, etc.) and get
a boolean mask that can be used to filter rows. ChunkExpandAtIndex Create a new ChunkedArray filled with values at that index. ChunkExplode Explode/flatten a List or String Series ChunkFillNullValue Replace None values with a value ChunkFilter Filter values by a boolean mask. ChunkFull Fill a ChunkedArray with one value. ChunkFullNull ChunkQuantile Quantile and median aggregation. ChunkReverse Reverse a ChunkedArray<T> ChunkRollApply rolling_windowThis differs from ChunkWindowCustom and ChunkWindow
by not using a fold aggregator, but reusing a Series wrapper and calling Series aggregators.
This likely is a bit slower than ChunkWindow ChunkSet Create a ChunkedArray with new values by index or by boolean mask. ChunkShift ChunkShiftFill Shift the values of a ChunkedArray ChunkSort Sort operations on ChunkedArray. ChunkTake ChunkTakeUnchecked ChunkUnique Get unique values in a ChunkedArray ChunkVar Variance and standard deviation aggregation. ChunkZip Combine two ChunkedArray ChunkedBuilder ChunkedCollectInferIterExt ChunkedCollectIterExt ChunkedSet polars-opsColumnBinaryUdf lazyA wrapper trait for any binary closure Fn(Column, Column) -> PolarsResult<Column> ColumnsUdf lazyA wrapper trait for any closure Fn(Vec<Series>) -> PolarsResult<Series> CrossJoin polars-opsCrossJoinFilter polars-opsDataFrameJoinOps polars-opsDataFrameOps polars-opsDateMethods temporalDatetimeMethods temporalDurationMethods temporalExprEvalExtension lazyFromData FromDataBinary FromDataUtf8 FunctionOutputField lazyGetAnyValue IndexToUsize InitHashMaps InitHashMaps2 IntoColumn Convert Self into a Column IntoGroupsType Used to create the tuples for a group_by operation. IntoLazy lazyIntoListNameSpace lazyIntoMetadata IntoScalar IntoSeries Used to convert a ChunkedArray&dyn SeriesTrait and SeriesSeries IntoVec Convenience for x.into_iter().map(Into::into).collect() using an into_vec() function. IsFirstDistinct is_first_distinctMask the first unique values as true IsLastDistinct is_last_distinctMask the last unique values as true JoinDispatch polars-opsLazyFileListReader lazyReads LazyFrame from a filesystem or a cloud storage.
Supports glob patterns. LhsNumOps ListBuilderTrait ListFromIter ListNameSpaceExtension lazyListNameSpaceImpl polars-opsLiteral lazyLogicalType MetaDataExt MinMaxHorizontal polars-opsNamedFrom NamedFromOwned NewChunkedArray NumOpsDispatch NumOpsDispatchChecked NumericNative PolarsDataType Safety PolarsFloatType PolarsIntegerType PolarsIterator A PolarsIteratorChunkedArrayPolarsIteratorExactSizeIteratorDoubleEndedIterator PolarsNumericType PolarsObject Values need to implement this so that they can be stored into a Series and DataFrame PolarsRound temporalPolarsTemporalGroupby lazyPolarsTruncate temporalPolarsUpsample temporalQuantileAggSeries Reinterpret reinterpretRenameAliasFn lazyRollingSeries polars-opsRoundSeries polars-opsSchemaExt SchemaExtPl SchemaNamesAndDtypes SerReader polars-ioSerWriter polars-ioSeriesJoin polars-opsSeriesMethods polars-opsSeriesOpsTime temporalSeriesRank polars-opsSeriesSealed polars-opsSeriesTrait SlicedArray Utility trait to slice concrete arrow arrays whilst keeping their
concrete type. E.g. don’t return Box<dyn Array>. StaticArray StringMethods temporalStringNameSpaceImpl polars-opsSumMeanHorizontal polars-opsTakeChunked polars-opsGather by ChunkId TakeChunkedHorPar polars-opsTemporalMethods temporalTimeMethods temporalToDummies polars-opsUdfSchema lazyVarAggSeries VecHash _coalesce_full_join polars-ops_join_suffix_name polars-ops_set_check_length ⚠ Meant for internal use. In very rare conditions this can be turned off. abs polars-opsConvert numerical values to their absolute value. all lazySelects all columns. Shorthand for col("*"). all_horizontal lazyCreate a new column with the bitwise-and of the elements in each row. any_horizontal lazyCreate a new column with the bitwise-or of the elements in each row. apply_binary lazyLike map_binary apply_multiple lazyApply a function/closure over the groups of multiple columns. This should only be used in a group_by aggregation. apply_projection polars-io and (ipc or ipc_streaming or parquet or avro)arange lazyGenerate a range of integers. arg_sort_by lazy and rangeFind the indexes that would sort these series in order of appearance. arg_where lazy and arg_whereGet the indices where condition evaluates true. as_struct lazyTake several expressions and collect them into a StructChunked avg lazyFind the mean of all the values in the column named name. Alias for mean base_utc_offset temporal and timezonesbinary_expr lazyCompute op(l, r) (or equivalently l op r). l and r must have types compatible with the Operator. call_categorical_merge_operation cast lazyCasts the column given by Expr to a different type. clip polars-opsSet values outside the given boundaries to the boundary value. clip_max polars-opsSet values above the given maximum to the maximum value. clip_min polars-opsSet values below the given minimum to the minimum value. coalesce lazyFolds the expressions from left to right keeping the first non-null values. coalesce_columns polars-opscol lazyCreate a Column Expression based on a column name. collect_all lazyCollect all LazyFrame cols lazySelect multiple columns by name. columns_to_projection polars-io and (ipc or ipc_streaming or avro or parquet)concat lazyConcat multiple LazyFrame concat_arr lazyHorizontally concatenate columns into a single array-type column. concat_expr lazyconcat_lf_diagonal lazy and diagonal_concatConcat LazyFrame s diagonally.
Calls concat concat_lf_horizontal lazyConcat LazyFrame s horizontally. concat_list lazyConcat lists entries. concat_str concat_str and strings and lazyHorizontally concat string columns in linear time convert_inner_type Cast null arrays to inner type and ensure that all offsets remain correct convert_to_unsigned_index polars-opscount_ones polars-opscount_rows polars-ioRead the number of rows without parsing columns
useful for count(*) queries count_rows_from_slice polars-ioRead the number of rows without parsing columns
useful for count(*) queries count_zeros polars-opscreate_enum_dtype dtype-categoricalcreate_sorting_map polars-iocum_count polars-opscum_fold_exprs lazy and dtype-structAccumulate over multiple columns horizontally / row wise. cum_max polars-opsGet an array with the cumulative max computed at every element. cum_min polars-opsGet an array with the cumulative min computed at every element. cum_prod polars-opsGet an array with the cumulative product computed at every element. cum_reduce_exprs lazy and dtype-structAccumulate over multiple columns horizontally / row wise. cum_sum polars-opsGet an array with the cumulative sum computed at every element date_ranges lazy and temporalCreate a column of date ranges from a start and stop expression. datetime lazyConstruct a column of Datetime from the provided DatetimeArgs datetime_range lazy and dtype-datetimeCreate a datetime range from a start and stop expression. datetime_ranges lazy and dtype-datetimeCreate a column of datetime ranges from a start and stop expression. datetime_to_timestamp_ms datetime_to_timestamp_ns datetime_to_timestamp_us decode_json_response polars-io and cloudUtility for decoding JSON that adds the response value to the error message if decoding fails.
This makes it much easier to debug errors from parsing network responses. default_join_ids polars-opsdeserialize polars-ioDeserializes the statistics in the column chunks from a single row_group
into Statisticsfield’s name. diff polars-opsdst_offset temporal and timezonesdtype_col lazySelect multiple columns by dtype. dtype_cols lazySelect multiple columns by dtype. duration lazyConstruct a column of DurationDurationArgs ensure_duration_matches_dtype temporalensure_is_constant_duration temporalensure_matching_schema escape_regex polars-opsescape_regex_str polars-opsexpand_paths polars-ioRecursively traverses directories and expands globs if glob is true. expand_paths_hive polars-ioRecursively traverses directories and expands globs if glob is true.
Returns the expanded paths and the index at which to start parsing hive
partitions from the path. expanded_from_single_directory polars-ioReturns true if expanded_paths were expanded from a single directory first lazyFirst column in a DataFrame. floor_div_series polars-opsfmt_group_by_column fold_exprs lazyAccumulate over multiple columns horizontally / row wise. format_str concat_str and strings and lazyFormat the results of an array of expressions using a format string get_encodings polars-ioget_glob_start_idx polars-ioGet the index of the first occurrence of a glob symbol. get_reader_bytes polars-ioget_strftime_format group_by_values temporalDifferent from group_by_windows, where define window buckets and search which values fit that
pre-defined bucket. group_by_windows temporalWindow boundaries are created based on the given Window, which is defined by: hor_str_concat polars-opsHorizontally concatenate all strings. impl_duration polars-opsimpl_replace_time_zone polars-opsimpl_replace_time_zone_fast polars-opsIf ambiguous is length-1 and not equal to “null”, we can take a slightly faster path. in_nanoseconds_window temporalindex_cols lazySelect multiple columns by index. indexes_to_usizes infer_file_schema polars-ioInfer the schema of a CSV file by reading through the first n rows of the file,
with max_read_rows controlling the maximum number of rows to read. infer_schema polars-ioInfers a ArrowSchemaFileMetadata int_range lazyGenerate a range of integers. int_ranges lazyGenerate a range of integers for each row of the input columns. interpolate polars-opsinterpolate_by polars-opsis_between polars-opsis_cloud_url polars-ioCheck if the path is a cloud url. is_first_distinct polars-opsis_in polars-opsis_last_distinct polars-opsis_not_null lazyA column which is false wherever expr is null, true elsewhere. is_null lazyA column which is true wherever expr is null, false elsewhere. is_positive_idx_uncertain polars-opsMay give false negatives because it ignores the null values. is_positive_idx_uncertain_col polars-opsMay give false negatives because it ignores the null values. last lazyLast column in a DataFrame. leading_ones polars-opsleading_zeros polars-opslen lazyReturn the number of rows in the context. linear_space lazyGenerate a series of equally-spaced points. lit lazyCreate a Literal Expression from L. A literal expression behaves like a column that contains a single distinct
value. make_categoricals_compatible make_list_categoricals_compatible map_binary lazyApply a closure on the two columns that are evaluated from ExprExpr map_list_multiple lazyApply a function/closure over multiple columns once the logical plan get executed. map_multiple lazyApply a function/closure over multiple columns once the logical plan get executed. materialize_empty_df polars-iomaterialize_projection polars-iomax lazyFind the maximum of all the values in the column named name. Shorthand for col(name).max(). mean lazyFind the mean of all the values in the column named name. Shorthand for col(name).mean(). median lazyFind the median of all the values in the column named name. Shorthand for col(name).median(). merge_dtypes min lazyFind the minimum of all the values in the column named name. Shorthand for col(name).min(). negate polars-opsnegate_bitwise polars-opsnew_int_range polars-opsnew_linear_space_f32 polars-opsnew_linear_space_f64 polars-opsnot lazyNegates a boolean column. nth lazyNth column in a DataFrame. overwrite_schema polars-io and jsonprepare_cloud_plan lazyPrepare the given DslPlan private_left_join_multiple_keys polars-opsquantile lazyFind a specific quantile of all the values in the column named name. reduce_exprs lazyAnalogous to Iterator::reduce remove_bom polars-iorepeat lazyCreate a column of length n containing n copies of the literal value. repeat_by polars-opsreplace polars-opsReplace values by different values of the same data type. replace_date temporal and dtype-dateReplace specific time component of a DateChunked with a specified value. replace_datetime temporal and dtype-datetimeReplace specific time component of a DatetimeChunked with a specified value. replace_or_default polars-opsReplace all values by different values. replace_strict polars-opsReplace all values by different values. replace_time_zone polars-opsresolve_homedir polars-ioReplaces a “~” in the Path with the home directory. split_helper polars-opssplit_to_struct polars-ops and dtype-structstr_join polars-opsstrip_chars polars-opsstrip_chars_end polars-opsstrip_chars_start polars-opsstrip_prefix polars-opsstrip_suffix polars-opssum lazySum all the values in the column named name. Shorthand for col(name).sum(). ternary_expr lazytime_ranges lazy and dtype-timeCreate a column of time ranges from a start and stop expression. trailing_ones polars-opstrailing_zeros polars-opstry_set_sorted_flag polars-iounique_counts polars-opsReturns a count of the unique values in the order of appearance. when lazyStart a when-then-otherwise expression. write_partitioned_dataset polars-ioWrite a partitioned parquet dataset. This functionality is unstable. AllowedOptimizations lazyAllowedOptimizations ArrayChunked dtype-arrayArrayRef ArrowSchema An ordered sequence of Field BinaryChunked BinaryChunkedBuilder BinaryOffsetChunked BooleanChunked BorrowIdxItem ChunkJoinOptIds polars-ops and chunked_idsDateChunked DatetimeChunked DecimalChunked DurationChunked FieldRef FieldsNameMapper lazy and dtype-structFileMetadataRef polars-ioFillNullLimit Float32Chunked Float64Chunked GetOutput lazyGroupsSlice Every group is indicated by an array where the IdxArr IdxCa Non-bigidx IdxItem IdxSize Non-bigidx IdxType Non-bigidx InnerJoinIds polars-opsInt8Chunked Int16Chunked Int32Chunked Int64Chunked Int128Chunked dtype-i128LargeBinaryArray LargeListArray LargeStringArray LeftJoinIds polars-opsListChunked ObjectChunked objectOpaqueColumnUdf lazyPlHashMap PlHashSet PlIdHashMap This hashmap uses an IdHasher PlIndexMap PlIndexSet PlRandomState PolarsResult QuantileInterpolOptions Deprecated RowGroupIterColumns polars-ioSchema SchemaRef StringChunked StringChunkedBuilder StructChunked TimeChunked TimeZone UInt8Chunked UInt16Chunked UInt32Chunked UInt64Chunked