Lazily read from a CSV file or multiple files via glob patterns. This allows the query optimizer to push down predicates and projections to the scan level.

Polars allows you to scan a CSV input. Scanning delays the actual parsing of the file and instead returns a lazy computation holder called a LazyFrame.

26 янв. 2024 г. · polars.scan_csv produces a query plan (called a LazyFrame ). You can then build you query and on the end call collect to materialize a ... Why polars.scan_csv is even faster than disk reading speed? What is the difference between read, scan, and sink in polars? Другие результаты с сайта stackoverflow.com

17 июн. 2024 г. · I'm working on larger-than-RAM csv.gz files that I want to convert to parquet. Just like in the docs, I would love to be able to do this.

The pl.scan_csv method won't actually read in all the data into memory. If you then call .fetch() then you'll retreive 5 (potentially random) rows of data.

Read a CSV file into a DataFrame. Values to interpret as null values. You can provide a: encoding {'utf8', 'utf8-lossy', ...} Set the sample size.

1 мар. 2023 г. · It would be nice if polars could load compressed csvs out of the box, e.g. a zstd compressed csv. I'm not sure what the best workaround is.

Read a CSV file in batches. Upon creation of the BatchedCsvReader , Polars will gather statistics and determine the file chunks. After that, work will only be ...

New LazyFrame from CSV. Description. Read a file from path into a polars LazyFrame. Usage. pl_scan_csv( source, ..., has_header = TRUE, separator = "," ...

8 дек. 2022 г. · This means that Polars takes care of scanning all the CSV files and concatenating them into a single LazyFrame; I called select on the ...