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Polars user guide

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[ pola-rs/polars  ](https://github.com/pola-rs/polars "Go to repository")

  * [ User guide ](/.)
  * [ API reference ](/api/)
  * [ Development ](/development/contributing/)
  * [ Releases ](/releases/changelog/)

[ ![logo](/_build/assets/logo.png) ](/. "Polars user guide") Polars user guide

[ pola-rs/polars  ](https://github.com/pola-rs/polars "Go to repository")

  * [ User guide  ](/.)

User guide

    * [ Getting started  ](/user-guide/getting-started/)
    * [ Installation  ](/user-guide/installation/)
    * [ Concepts  ](/user-guide/concepts/)

Concepts

      * Data types  Data types 
        * [ Overview  ](/user-guide/concepts/data-types/overview/)
        * [ Categorical data  ](/user-guide/concepts/data-types/categoricals/)
      * [ Data structures  ](/user-guide/concepts/data-structures/)
      * [ Contexts  ](/user-guide/concepts/contexts/)
      * [ Expressions  ](/user-guide/concepts/expressions/)
      * [ Lazy / eager API  ](/user-guide/concepts/lazy-vs-eager/)
      * [ Streaming API  ](/user-guide/concepts/streaming/)
    * [ Expressions  ](/user-guide/expressions/)

Expressions

      * [ Basic operators  ](/user-guide/expressions/operators/)
      * [ Column selections  ](/user-guide/expressions/column-selections/)
      * [ Functions  ](/user-guide/expressions/functions/)
      * [ Casting  ](/user-guide/expressions/casting/)
      * [ Strings  ](/user-guide/expressions/strings/)
      * [ Aggregation  ](/user-guide/expressions/aggregation/)
      * [ Missing data  ](/user-guide/expressions/missing-data/)
      * [ Window functions  ](/user-guide/expressions/window/)
      * [ Folds  ](/user-guide/expressions/folds/)
      * [ Lists and Arrays  ](/user-guide/expressions/lists/)
      * [ Expression plugins  ](/user-guide/expressions/plugins/)
      * [ User-defined functions (Python)  ](/user-guide/expressions/user-defined-functions/)
      * [ The Struct datatype  ](/user-guide/expressions/structs/)
      * [ Numpy  ](/user-guide/expressions/numpy/)
    * [ Transformations  ](/user-guide/transformations/)

Transformations

      * [ Joins  ](/user-guide/transformations/joins/)
      * [ Concatenation  ](/user-guide/transformations/concatenation/)
      * [ Pivots  ](/user-guide/transformations/pivot/)
      * [ Melts  ](/user-guide/transformations/melt/)
      * Time series  Time series 
        * [ Parsing  ](/user-guide/transformations/time-series/parsing/)
        * [ Filtering  ](/user-guide/transformations/time-series/filter/)
        * [ Grouping  ](/user-guide/transformations/time-series/rolling/)
        * [ Resampling  ](/user-guide/transformations/time-series/resampling/)
        * [ Time zones  ](/user-guide/transformations/time-series/timezones/)
    * [ Lazy API  ](/user-guide/lazy/)

Lazy API

      * [ Usage  ](/user-guide/lazy/using/)
      * [ Optimizations  ](/user-guide/lazy/optimizations/)
      * [ Schema  ](/user-guide/lazy/schemas/)
      * [ Query plan  ](/user-guide/lazy/query-plan/)
      * [ Query execution  ](/user-guide/lazy/execution/)
      * [ Streaming  ](/user-guide/lazy/streaming/)
    * [ IO  ](/user-guide/io/)

IO

      * [ CSV  ](/user-guide/io/csv/)
      * [ Excel  ](/user-guide/io/excel/)
      * [ Parquet  ](/user-guide/io/parquet/)
      * [ JSON files  ](/user-guide/io/json/)
      * [ Multiple  ](/user-guide/io/multiple/)
      * [ Databases  ](/user-guide/io/database/)
      * [ Cloud storage  ](/user-guide/io/cloud-storage/)
      * [ Google BigQuery  ](/user-guide/io/bigquery/)
    * SQL  SQL 
      * [ Introduction  ](/user-guide/sql/intro/)
      * [ SHOW TABLES  ](/user-guide/sql/show/)
      * [ SELECT  ](/user-guide/sql/select/)
      * [ CREATE  ](/user-guide/sql/create/)
      * [ Common Table Expressions  ](/user-guide/sql/cte/)
    * Migrating  Migrating 
      * [ Coming from Pandas  ](/user-guide/migration/pandas/)
      * [ Coming from Apach