Rust Comment Readability Fixes (#3662)

Signed-off-by: Ryan Russell <git@ryanrussell.org>

polars/src/docs/eager.rs

@@ -281,7 +281,7 @@
 //!                 })
 //!                 .collect()
 //!         }
-//!         _ => panic!("unpexptected dtypes"),
+//!         _ => panic!("unexpected dtypes"),
 //!     }
 //! }
 //! ```
@@ -403,7 +403,7 @@
 //! ## Groupby
 //!
 //! Note that Polars lazy is a lot more powerful in and more performant in groupby operations.
-//! In lazy a meriad of aggregations can be combined from expressions.
+//! In lazy a myriad of aggregations can be combined from expressions.
 //!
 //! See more in:
 //!

polars/src/docs/lazy.rs

@@ -199,7 +199,7 @@
 //! ## Conditionally apply
 //! If we want to create a new column based on some condition, we can use the `.when()/.then()/.otherwise()` expressions.
 //!
-//! * `when` - accepts a predicate epxression
+//! * `when` - accepts a predicate expression
 //! * `then` - expression to use when `predicate == true`
 //! * `otherwise` - expression to use when `predicate == false`
 //!

polars/src/lib.rs

@@ -296,7 +296,7 @@
 //! * `POLARS_TABLE_WIDTH` -> width of the tables used during DataFrame formatting.
 //! * `POLARS_MAX_THREADS` -> maximum number of threads used to initialize thread pool (on startup).
 //! * `POLARS_VERBOSE` -> print logging info to stderr
-//! * `POLARS_NO_PARTITION` -> Polars may choose to partition the groupby operaiton, based on data
+//! * `POLARS_NO_PARTITION` -> Polars may choose to partition the groupby operation, based on data
 //!                            cardinality. Setting this env var will turn partitioned groupby's off
 //! * `POLARS_PARTITION_SAMPLE_FRAC` -> how large chunk of the dataset to sample to determine cardinality,
 //!                                     defaults to `0.001`