🌽💪 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.

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Installation

pip install paramiko polars chardet

Then drop cornflex/ into your project.

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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",
)

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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"]

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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()

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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()

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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()

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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.

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Dependencies

Package	Purpose
paramiko	SSH/SFTP connection
polars	DataFrame output
chardet	Encoding detection