readme / and minor fixes

README.md

@@ -115,9 +115,9 @@ Rust crate `polars` itself. However, both the Python package and the Python modu
 can `pip install polars` and `import polars` (previously, these were called `py-polars` and `pypolars`).
 
 ## Arrow2
-Polars has a fully functional [arrow2](https://crates.io/crates/arrow2) branch and will ship the python binaries
-from this branch. Arrow2 is a faster and safer implementation of the arrow spec. Arrow2 also has a more granular code base,
-helping to reduce the compiler bloat.
+Polars has transitioned to [arrow2](https://crates.io/crates/arrow2). Arrow2 is a faster and safer implementation of the arrow spec. 
+Arrow2 also has a more granular code base, helping to reduce the compiler bloat.
+There is still a maintained `arrow-rs` branch for users who want to use another backend.
 
 ## Acknowledgements
 Development of Polars is proudly powered by

polars/polars-core/src/frame/mod.rs

@@ -526,7 +526,7 @@ impl DataFrame {
         } else {
             Err(PolarsError::ShapeMisMatch(
                 format!(
-                    "Could add column. The Series length {} differs from the DataFrame height: {}",
+                    "Could not add column. The Series length {} differs from the DataFrame height: {}",
                     series.len(),
                     self.height()
                 )
@@ -557,7 +557,7 @@ impl DataFrame {
         } else {
             Err(PolarsError::ShapeMisMatch(
                 format!(
-                    "Could add column. The Series length {} differs from the DataFrame height: {}",
+                    "Could not add column. The Series length {} differs from the DataFrame height: {}",
                     series.len(),
                     self.height()
                 )

py-polars/polars/eager/series.py

@@ -186,6 +186,10 @@ def __init__(
         dtype: Optional[Type[DataType]] = None,
         strict: bool = True,
     ):
+        # this prevents errors with users setting dtype to nullable
+        if not isinstance(nullable, bool):
+            raise ValueError(f"invalid type set to nullable: {type(nullable)}")
+
         # Handle case where values are passed as the first argument
         if name is not None and not isinstance(name, str):
             if values is None: