FTP Data Processor

Build a Python module that downloads a CSV file from an FTP server, processes it in-memory, and uploads the processed result back to the server without writing to disk.

Requirements

Your module should provide a function that:

1. Downloads a CSV file from a remote FTP server directly into memory (no disk I/O)
2. Processes the CSV data by:
   • Converting all text values to uppercase
   • Filtering out rows where the first column is empty
3. Uploads the processed CSV back to the FTP server directly from memory (no disk I/O)
4. Returns the number of rows processed (excluding header)

The function should accept:

• FTP connection details (host, username, password)
• Remote file path for the source CSV
• Remote file path for the destination CSV

Implementation { .implementation }

@generates

API { #api }

def process_ftp_csv(
    ftp_host: str,
    ftp_user: str,
    ftp_password: str,
    source_path: str,
    dest_path: str
) -> int:
    """
    Download CSV from FTP, process in-memory, and upload result.

    Args:
        ftp_host: FTP server hostname
        ftp_user: FTP username
        ftp_password: FTP password
        source_path: Remote path to source CSV file
        dest_path: Remote path to destination CSV file

    Returns:
        Number of data rows processed (excluding header)
    """
    pass

Test Cases

• Given a CSV with 3 data rows (plus header) containing mixed case text and no empty first columns, the function processes all 3 rows and returns 3 @test
• Given a CSV with 5 data rows where 2 rows have empty first columns, the function processes only 3 rows and returns 3 @test
• The processed CSV uploaded to the FTP server has all text values in uppercase @test

Dependencies { .dependencies }

apache-airflow-providers-ftp { .dependency }

Provides FTP operations support for file transfer and server interaction.

@satisfied-by