A Beginner's Guide to Uploading Files with Python Requests

Requests is a popular Python library that makes it easy to send HTTP requests. This is helpful for web scraping and interacting with APIs. One common task is uploading files via a POST request. In this guide, I'll walk through how to do this in Requests step-by-step.

An Introduction to Requests

First, what exactly is Requests? It's a Python module that provides a simple interface for making HTTP calls. The key benefit is that it abstracts away a lot of the low-level details of dealing with HTTP requests and responses for you.

Some key features of Requests:

Requests makes it super easy to do things like scrape web pages, interact with APIs, upload files, and more!

Our Goal

In this guide, I'm going to walk through the process for uploading files via Requests, step-by-step. We'll start simple with a single file upload, then look at uploading multiple files in one go. I'll also cover some more advanced options you may need to use.

My goal is to provide you with a solid understanding of the key concepts so you can apply them in your own projects. Let's get to it!

Uploading a Single File

Uploading a single file with Requests is straightforward. There are just a few steps we need to follow:

Step 1: Open the File and Get the Bytes

First, we need to open the file we want to upload and read its bytes. This is so Requests can determine the body and content-length to send.

We use the built-in open() function for this. Pass it the filename and "rb" mode to get bytes:

f = open("file.jpg", "rb")
file_bytes = f.read()

The "b" is key - it returns bytes which Requests needs.

Step 2: Create a Files Dict with the Bytes

Next, we need to create a dictionary with the file bytes to pass to Requests. This tells it what to upload.

I like to structure it as a tuple with the filename, bytes, and optional content-type:

files = {
    "myfile": ("file.jpg", file_bytes, "image/jpeg")
}

The key can be any field name you want.

Step 3: Make the POST Request

Now we can make the POST request, passing the files dict:

url = "<https://api.example.com/upload>"

r = requests.post(url, files=files)

This will upload the file for us. All we had to do was open the file and provide the bytes!

Step 4: Check the Response

Finally, we should check the response status code to confirm the upload succeeded:

if r.status_code == 201:
    print("Upload successful!")
else:
    print("Upload failed!")

And that's it for a basic single file upload with Requests! Pretty easy right?

Now let's look at uploading multiple files...

Uploading Multiple Files

To upload multiple files in a single request, we just need to add additional key/value pairs to our files dictionary.

For example:

files = {
  "file1": ("report.pdf", pdf_bytes),
  "file2": ("presentation.pptx", pptx_bytes)
}

Then pass this to .post() like before:

r = requests.post(url, files=files)

Requests will upload all the files concurrently. Awesome!

Some tips when uploading multiple files:

And that's the basics of multiple file uploads! Next let's look at some additional options...

Additional Options

There are a few other options you may need to use when uploading files:

Headers

You can pass custom headers for things like content-type and authentication:

headers = {"Authorization": "Bearer mytoken"}

requests.post(url, files=files, headers=headers)

Data and JSON

You can also send data and JSON bodies alongside your files:

data = {"key": "value"}
json = {"key": "value"}

requests.post(url, files=files, data=data, json=json)

Note that json overrides data if both are passed.

Redirects

By default Requests will follow redirects, but you can disable this:

requests.post(url, files=files, allow_redirects=False)

Timeouts

Use the timeout parameter to avoid hanging requests:

requests.post(url, files=files, timeout=3.05)

Authentication

Pass HTTP Basic Auth or Digest Auth tuples:

requests.post(url, files=files, auth=('user','pass'))

This covers some of the key options you may need to use alongside file uploads.

Handling Errors

When uploading files, errors can occur like:

Always check the status code to catch errors.

For example:

r = requests.post(url, files=files)

if 400 <= r.status_code < 500:
  print("Client error:", r.text)
elif 500 <= r.status_code < 600:
  print("Server error")

This prints custom error messages based on the status code.

You can also use try/except blocks to handle specific exceptions nicely:

try:
  r = requests.post(url, files=files, timeout=10)
  r.raise_for_status()

except requests.Timeout as e:
  print("Timeout occurred, try again")

except requests.HTTPError as e:
  print("HTTP error occurred:", e)

This lets you handle timeouts and HTTP errors independently.

Debugging file uploads can be tricky, so take time to handle errors properly in your code.

Recap and Key Takeaways

Let's recap what we learned:

The key points are:

That covers the basics and best practices of uploading files with Python Requests!

Next Steps

To dive deeper:

I hope you found this guide helpful! Let me know if you have any other questions.

Now you're ready to start uploading files via Requests in your own projects. Good luck!