Pyarrow.lib.arrowtypeerror: expected a string or bytes dtype, got float64

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When encountering the error message “pyarrow.lib.arrowtypeerror: expected a string or bytes dtype, got float64,” it means that the PyArrow library was expecting a string or bytes data type but received a float64 data type instead.

To understand this better, let’s go through an example:

    
import pyarrow as pa

# Define a schema with a string field
schema = pa.schema([("name", pa.string())])

# Create a table with invalid float64 data
data = [
    (3.14,),
    (2.71,),
    (4.20,)
]

# Create a RecordBatch with the invalid data
record_batch = pa.RecordBatch.from_pandas(pd.DataFrame(data), schema=schema)

# This will raise an ArrowTypeError
pa.Table.from_batches([record_batch])

In the above example, we defined a schema that expects a string field. However, we provided a float64 value instead. When trying to create a RecordBatch with this data and convert it to a table using the pa.Table.from_batches method, the expected string or bytes data type was not met, resulting in the mentioned error.

To fix this error, ensure that the data being passed to PyArrow matches the expected data type. In the above example, you can modify the data to contain strings instead of floats:

    
data = [
    ("John",),
    ("Alice",),
    ("Bob",)
]

By providing the correct string values, the error will be resolved.

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