Known Divergences

Intentional and unintentional differences between cqlsh-rs and Python cqlsh.

Intentional differences

TLS/SSL

cqlsh-rs uses rustls, which does not support SSLv3, TLSv1.0, or TLSv1.1.
The [ssl] version config key accepts TLSv1_2 and TLSv1_3 only.

Driver

cqlsh-rs uses the scylla-rust-driver instead of the Python cassandra-driver.
Token-aware routing and connection pooling behavior may differ.
Protocol version negotiation may select a different version in edge cases.

COPY implementation

Python cqlsh uses multiprocessing for COPY operations.
cqlsh-rs uses async I/O (tokio), which may behave differently under heavy load.
Error messages during COPY operations may differ in format.

cqlsh-rs uses a built-in pager (sapling-streampager) instead of shelling out to less.
The PAGING <N> command accepts a page size for compatibility but uses the built-in pager.

Minor formatting differences

Floating-point formatting may show trailing zeros differently in edge cases.
Timestamp formatting uses chrono instead of Python’s datetime, which may produce slightly different results for edge-case timezone handling.
Blob values are displayed identically (0x...) but internal formatting may differ for very large blobs.

Missing features (planned)

These features from Python cqlsh are not yet implemented but are planned:

COPY FROM (partially implemented)
Per-topic HELP text (stub implementation)
CQL type-specific formatting customization

Reporting divergences

If you find a behavior difference not listed here, please open an issue.