test_loader.py

import os

# Mock loader classes for demonstration purposes
class PyPDFLoader:
    def __init__(self, file_path):
        self.file_path = file_path
        print(f'PDF loader initialized with {file_path}')

class TextLoader:
    def __init__(self, file_path):
        self.file_path = file_path
        print(f'Text loader initialized with {file_path}')

class CSVLoader:
    def __init__(self, file_path):
        self.file_path = file_path
        print(f'CSV loader initialized with {file_path}')

# Function to determine the loader based on file extension
def get_loader_by_file_extension(temp_file):
    if not isinstance(temp_file, str):
        raise TypeError("Expected file path as a string.")
    
    file_split = os.path.splitext(temp_file)
    file_extension = file_split[1]  # Extract the extension
    print('file_extension - ', file_extension)

    # Initialize loader based on file extension
    if file_extension == '.pdf':
        loader = PyPDFLoader(temp_file)
        print('Loader Created for PDF file')
    elif file_extension == '.txt':
        loader = TextLoader(temp_file)
    elif file_extension == '.csv':
        loader = CSVLoader(temp_file)
    else:
        raise ValueError(f"Unsupported file type: {file_extension}")

    return loader

# Test the function with different file types
if __name__ == "__main__":
    test_files = [
        "document.pdf",
        "notes.txt",
        "data.csv",
        "image.jpg"  # This should raise an error
    ]

    for test_file in test_files:
        print(f"\nTesting with file: {test_file}")
        try:
            loader = get_loader_by_file_extension(test_file)
        except Exception as e:
            print(f'Error: {e}')