4 releases
Uses new Rust 2024
| 0.2.0 | Jul 27, 2026 |
|---|---|
| 0.1.2 | Jun 22, 2026 |
| 0.1.1 | Jun 21, 2026 |
| 0.1.0 | Jun 8, 2026 |
#37 in #pandas
537 downloads per month
Used in 5 crates
(4 directly)
12MB
266K
SLoC
fp-io
IO layer for frankenpandas: CSV, JSON, JSONL, Parquet, Excel, Feather, Arrow IPC, SQL.
Part of the frankenpandas workspace.
Supported formats
| Format | Read | Write | Options |
|---|---|---|---|
| CSV | read_csv_str / read_csv |
write_csv_string |
delimiter, na_values, index_col, usecols, nrows, skiprows, dtype |
| JSON | read_json_str / read_json |
write_json_string |
5 orients (Records, Columns, Index, Split, Values) |
| JSONL | read_jsonl_str / read_jsonl |
write_jsonl_string |
One object per line, union-key detection |
| Parquet | read_parquet_bytes / read_parquet |
write_parquet_bytes |
Arrow RecordBatch integration |
| Excel | read_excel_bytes / read_excel |
write_excel_bytes |
sheet_name, has_headers, index_col |
| Feather | read_feather_bytes |
write_feather_bytes |
Arrow IPC file + stream |
| Arrow IPC | read_ipc_stream_bytes |
write_ipc_stream_bytes |
Stream format |
| SQL | read_sql / read_sql_table |
write_sql |
SqlConnection trait; SQLite today |
SQL backend expansion (PostgreSQL / MySQL) is tracked under br-frankenpandas-fd90 (slices 2-3 open).
When to depend on fp-io directly
Most users should depend on the umbrella frankenpandas crate
which re-exports the IO functions. Direct dependency makes sense
when:
- You need IO primitives but not the full DataFrame arithmetic layer.
- You are writing a streaming pipeline that routes through
fp-columnarwithout materializing a full DataFrame.
Status
Stable for covered formats. Fuzz regression corpus runs on every
PR (br-frankenpandas-zjme). Differential conformance against live
pandas runs in CI (br-frankenpandas-d6xa). IoError is
#[non_exhaustive] per br-frankenpandas-tne4.
Links
- Workspace README
- Security policy — IO parsers are the primary in-scope surface for vulnerability reports.
Dependencies
~60MB
~1M SLoC