Fastexcel

Warnings

• breaking Fastexcel has dropped support for older Python versions. v0.17.1 dropped Python 3.9, and v0.13.0 dropped Python 3.8. The current minimum required Python version is 3.10.
  Fix: Ensure your Python environment is version 3.10 or higher before installing or upgrading fastexcel.
• gotcha Setting `schema_sample_rows=0` when initializing `Reader` is no longer allowed and will raise an error.
  Fix: Use a positive integer for `schema_sample_rows` to infer the schema from actual rows, or omit it entirely to use the default behavior (which is usually sufficient).
• gotcha Prior to v0.17.1, cells containing Excel error values like `#DIV/0!` might not have been consistently treated as null during type inference.
  Fix: Upgrade to `fastexcel` v0.17.1 or later to ensure that `#DIV/0!` cells are correctly interpreted as null values.
• gotcha In versions prior to v0.19.0, using `use_columns` with `load_table` when `column_names` was *not* specified could lead to incorrect behavior or errors.
  Fix: Upgrade to `fastexcel` v0.19.0 or later. If upgrading is not possible, ensure that `column_names` is also explicitly provided when using `use_columns` in older versions.

Install

• pip install fastexcel Install Fastexcel

Imports

• Reader

  from fastexcel import Reader

Quickstart

This quickstart demonstrates how to read an Excel file using `fastexcel`. It first creates a dummy Excel file with pandas, then initializes `fastexcel.Reader` to load data into an Apache Arrow Table, showing how to read by sheet index and sheet name.

import pandas as pd
from fastexcel import Reader
import os

# Create a dummy Excel file for demonstration
file_path = "dummy_data.xlsx"
data = {'ColumnA': [1, 2, 3], 'ColumnB': ['X', 'Y', 'Z']}
df = pd.DataFrame(data)
df.to_excel(file_path, index=False)

try:
    # Initialize the reader with the Excel file path
    reader = Reader(file_path)

    # Load the first sheet into an Apache Arrow Table
    table = reader.load_table(sheet_name=0)
    print("\nData from first sheet (Arrow Table):")
    print(table)

    # To access sheet names, first call load_ws()
    reader.load_ws() # Loads all worksheet metadata
    if reader.ws_names:
        first_sheet_name = reader.ws_names[0]
        table_by_name = reader.load_table(sheet_name=first_sheet_name)
        print(f"\nData from sheet '{first_sheet_name}' by name:")
        print(table_by_name)

except Exception as e:
    print(f"An error occurred: {e}")
finally:
    # Clean up the dummy file
    if os.path.exists(file_path):
        os.remove(file_path)
        print(f"\nCleaned up {file_path}")