Loading CSV and Excel files in LangChain

Introduction

Loading CSV and Excel files lets you bring data from spreadsheets into your program easily. This helps you work with real-world data like lists, tables, or reports.

You have a spreadsheet with customer information and want to analyze it.

You want to read a CSV file with sales data to create charts.

You need to load an Excel file with multiple sheets for a report.

You want to process data exported from another program in CSV or Excel format.

Syntax

LangChain

from langchain.document_loaders import CSVLoader, ExcelLoader

# Load CSV file
csv_loader = CSVLoader(file_path="path/to/file.csv")
csv_docs = csv_loader.load()

# Load Excel file
excel_loader = ExcelLoader(file_path="path/to/file.xlsx")
excel_docs = excel_loader.load()

Use CSVLoader for CSV files and ExcelLoader for Excel files.

The load() method reads the file and returns documents you can use in LangChain.

Examples

This loads a CSV file named customers.csv from the data folder.

LangChain

from langchain.document_loaders import CSVLoader

csv_loader = CSVLoader(file_path="data/customers.csv")
docs = csv_loader.load()

This loads an Excel file named sales.xlsx from the data folder.

LangChain

from langchain.document_loaders import ExcelLoader

excel_loader = ExcelLoader(file_path="data/sales.xlsx")
docs = excel_loader.load()

This loads only the "Summary" sheet from the Excel file.

LangChain

from langchain.document_loaders import ExcelLoader

# Load specific sheet by name
excel_loader = ExcelLoader(file_path="data/report.xlsx", sheet_name="Summary")
docs = excel_loader.load()

Sample Program

This program loads two files: a CSV and an Excel file. It prints how many documents each file contains after loading.

LangChain

from langchain.document_loaders import CSVLoader, ExcelLoader

# Load CSV file
csv_loader = CSVLoader(file_path="example_data.csv")
csv_docs = csv_loader.load()
print(f"Loaded {len(csv_docs)} documents from CSV file.")

# Load Excel file
excel_loader = ExcelLoader(file_path="example_data.xlsx")
excel_docs = excel_loader.load()
print(f"Loaded {len(excel_docs)} documents from Excel file.")

Important Notes

Make sure the file paths are correct and files exist to avoid errors.

Excel files can have multiple sheets; you can specify which sheet to load.

The loaded documents are ready to be used in LangChain workflows like text processing or question answering.

Summary

Use CSVLoader and ExcelLoader to load spreadsheet files easily.

Loading files turns spreadsheet data into documents LangChain can work with.

You can specify sheet names for Excel files to load only needed data.