Alright ! Let’s talk about FTP (File Transfer Protocol) and how we can use Python to automate our file transfers with ease. If you’re not familiar with FTP, it’s an ancient protocol that allows us to transfer files over the internet using a client-server model.
But who wants to spend their time clicking around in some clunky FTP client when we can use Python instead? Let’s get right into it with how to do this!
First things first, let’s install the `ftplib` library which will allow us to interact with an FTP server using Python. To do this, open up your terminal or command prompt (depending on your operating system) and type:
# This script installs the `ftplib` library using the `pip` command.
# First, we need to import the `ftplib` library.
import ftplib
# Next, we need to create a variable `ftp` that will store our FTP connection.
ftp = ftplib.FTP()
# Now, we need to connect to the FTP server using the `connect()` method and passing in the server address and port number.
ftp.connect("server_address", port_number)
# We also need to login to the FTP server using the `login()` method and passing in the username and password.
ftp.login("username", "password")
# Once we are connected and logged in, we can start interacting with the FTP server.
# For example, we can use the `retrbinary()` method to retrieve a file from the server and save it locally.
ftp.retrbinary("RETR file_name", open("local_file_name", "wb").write)
# After we are done interacting with the FTP server, we can close the connection using the `quit()` method.
ftp.quit()
# Finally, we can print a message to indicate that the script has successfully completed.
print("FTP connection and file transfer completed successfully.")
Once that’s done, let’s write some code! Here’s a basic example of how to connect to an FTP server using Python.
# Import the ftplib module to access FTP functionalities
import ftplib
# Connect to the FTP server using the domain name
ftp = ftplib.FTP('example.com')
# Login with your credentials (if required)
ftp.login('your_username', 'your_password')
# Change directory on the remote server
ftp.cwd('/path/to/directory')
# Download a file from the FTP server and save it locally
with open('local_file.txt', 'wb') as f:
# Use the retrbinary() method to retrieve a file from the server and write it to the local file
ftp.retrbinary('RETR filename.txt', f.write)
In this example, we’re connecting to an FTP server at `example.com`, logging in with our credentials (if required), changing directory on the remote server, and downloading a file called `filename.txt`. The `with open()` statement is used to create or overwrite the local file that will receive the contents of the remote file.
But what if we want to list all the files in a specific directory? We can use Python’s built-in `os` module and the FTP library’s `dir()` method for this. Here’s an example:
# Import the necessary libraries
import ftplib # Import the FTP library
import os # Import the os module for file operations
# Connect to the FTP server
ftp = ftplib.FTP('example.com') # Create an FTP object and connect to the server
# Login with your credentials (if required)
ftp.login('your_username', 'your_password') # Use the login method to authenticate with the server
# Change directory on the remote server
ftp.cwd('/path/to/directory') # Use the cwd method to change the current working directory on the server
# List all files in the current directory using Python's os module
files = [] # Create an empty list to store the file names
for file in ftp.dir(): # Use the dir method to list all files in the current directory on the server
if not file[0].isdigit() and '.' in file: # Check if the file is not a directory and has a file extension
files.append(ftp.size(file)[0]) # Use the size method to get the file size and add it to the list
print(f"{ftp.size(file)[1]} {os.path.basename(file)}") # Print the file size and name using the os module's basename function
# Close the FTP connection
ftp.quit() # Use the quit method to close the connection with the server
In this example, we’re using a `for` loop to iterate over the results of calling the FTP library’s `dir()` method. We’re filtering out directories and non-file items (e.g., ., ..) by checking if the first character is not a digit and there’s a dot in the filename.
We hope this helps you get started with using Python to automate your FTP file transfers!