read_csv(source="path.csv", encoding="utf8", null_values="null") df = pl.read_parquet() # 在大数据场景存储和处理方面有优势 # 惰性读取 # 延迟了对文件的实际解析,并返回一个延迟计算的容器LazyFrame lazy_df = pl.scan_csv("path.csv") lazy_df = p
然后读取 CSV 文件除了 read_csv 函数之外,还有 scan_csv,这两个函数的用法和参数都是一样的。但区别是 read_csv 会立即加载整个 CSV 文件到内存中,并返回一个完成的 DataFrame,当数据集可以被完整地载入内存时 read_csv 非常适合。 scan_csv 函数采用一种懒加载的方式来处理数据,它并不立即加载整个文件,而是...
One-hot encoding df.to_dummies Array of hashes df.rows(named:true) Hash of series df.to_h CSV df.to_csv# ordf.write_csv("file.csv") Parquet df.write_parquet("file.parquet") JSON df.write_json("file.json")# ordf.write_ndjson("file.ndjson") ...
write_options; // 16MB const DEFAULT_ALLOCATION_SIZE: usize = 1 << 24; // Encode task. // // Task encodes the columns into their corresponding CSV encoding. for (mut receiver, mut sender) in receivers.into_iter().zip(senders) { for (mut receiver, sender) in receivers.into_iter()....
"urlencoding", ] [[package]] name = "aws-smithy-runtime" version = "1.6.0" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "db83b08939838d18e33b5dbaf1a0f048f28c10bd28071ab7ce6f245451855414" dependencies = [ "aws-smithy-async", "aws-smithy...
'feature="io_avro_compression"' --cfg 'feature="io_csv_write"' --cfg 'feature="io_ipc"' --cfg 'feature="io_ipc_compression"' --cfg 'feature="io_json"' --cfg 'feature="io_parquet"' --cfg 'feature="io_parquet_compression"' --cfg 'feature="lexical-core"' --cfg 'feature="lib...
// Task encodes the columns into their corresponding CSV encoding. join_handles.extend(rxs.into_iter().zip(lin_txs).map(|(mut rx, mut lin_tx)| { join_handles.extend(pass_rxs.into_iter().map(|mut pass_rx| { let schema = self.schema.clone(); ...
OSError: failed to write whole buffer Issue description Collecting the data into a StringIO before passing it to polars with e.g. restringified=io.StringIO(wrapper.read())pl.read_csv(restringified) works, though is no longer a streaming operation. ...
sys:1: CategoricalRemappingWarning: Local categoricals have different encodings, expensive re-encoding is done to perform this merge operation. Consider using a StringCache or an Enum type if the categories are known in advance parquet scan with parallel = RowGroups parquet row group must be read...
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