🌽💪 Cornflex 🌽💪

A lightweight SFTP reader built on top of paramiko and polars. Connects to remote servers and pulls files down as strings, Polars DataFrames, or raw text.

Installation

pip install paramiko polars chardet

Then drop cornflex/ into your project.

Usage

from cornflex import SFTPReader

Connect with password

reader = SFTPReader(
    hostname="sftp.example.com",
    username="myuser",
    password="mypassword",
)

Connect with PEM key

reader = SFTPReader(
    hostname="sftp.example.com",
    username="myuser",
    pem_file="/path/to/key.pem",
)

Methods

get_files(remote_path, file_pattern)

Lists files in a remote directory. Supports glob-style patterns.

reader.get_files(remote_path="/data", file_pattern="*.csv")
# ["orders_2024.csv", "users_2024.csv"]

get_csv_file(file_name, remote_path, column_names)

Fetches a CSV and returns it as a Polars DataFrame.

reader.connect()
df = reader.get_csv_file("orders.csv", remote_path="/data")

# Override column names (useful when file has no header)
df = reader.get_csv_file("orders.csv", remote_path="/data", column_names=["id", "amount", "date"])
reader.close()

get_xml_file_to_string(file_name, remote_path)

Fetches an XML file and returns it as a string.

reader.connect()
xml = reader.get_xml_file_to_string("feed.xml", remote_path="/exports")
reader.close()

file_to_string(file_name, remote_path, encoding)

Fetches any file as a string. Auto-detects encoding via chardet if not specified.

reader.connect()
content = reader.file_to_string("report.txt", remote_path="/reports")

# Force encoding
content = reader.file_to_string("report.txt", encoding="latin-1")
reader.close()

Notes

• get_files() handles connect/close internally.
• For all other methods, call connect() before and close() after.
• Either password or pem_file must be provided — not both, not neither.
• get_csv_file assumes UTF-8. Use file_to_string for other encodings.

Dependencies