Python http file upload

How to upload a file and some data through HTTP multipart in Python 3 using the requests library

Undeniably, the HTTP protocol had become the dominant communication protocol between computers.

Through the HTTP protocol, a HTTP client can send data to a HTTP server. For example, a client can upload a file and some data from to a HTTP server through a HTTP multipart request.

If you are building that client with Python 3, then you can use the requests library to construct the HTTP multipart request easily.

In case you need it, this is how we can upload a file and some data through HTTP multipart in Python 3 using the requests library.

1. Define the file upload scenario

First, let us define the file upload scenario.

Assume that we are building a Python 3 application for your Raspberry Pi 3. Whenever a button is pressed, an image will be captured with the camera on your Raspberry Pi along with temperature read from a DHT11 sensor.

Given that, we will be building a function that will take a file path to an image and a float value for the temperature as input parameters. Given that, the function will upload the image file and the temperature to a server endpoint at http://www.example.com/api/v1/sensor_data .

2. Install the requests library

In order to use the requests library, we need to install it by running the following pip command inside your Python environment:

If you are using a virtual environment to run your Python application on your Raspberry Pi, then you can run the command after activating the virtual environment.

3. Write the Python 3 function to upload the image file and temperature to the server endpoint

After you had installed the requests library, we can use the following codes to upload the image file and temperature value via a HTTP multipart request:

import requests import os function send_data_to_server(image_path, temperature): image_filename = os.path.basename(image_path) multipart_form_data = < 'image': (image_filename, open(image_path, 'rb')), 'temperature': ('', str(temperature)), >response = requests.post('http://www.example.com/api/v1/sensor_data/', files=multipart_form_data) print(response.status_code)

The send_data_to_server function accepts a path to an image and a temperature value as its input value. Once the function is being called, it first get the filename of the image from the path.

After that, it constructs a dictionary with two multipart variables — image and temperature . Both variables and their values are represented by 2-tuples. The image variable is assigned a filename and a file handle to the actual image. On the other hand, as temperature is a single value, the first element of the 2-tuple is empty while the second element contains the temperature as a string.

Once we had constructed the dictionary to represent the content, we call requests.post to send a HTTP multipart request to the server endpoint at http://www.example.com/api/v1/sensor_data/ .

Lastly, the function prints the status of the HTTP response received from the server.

About Clivant

Clivant a.k.a Chai Heng enjoys composing software and building systems to serve people. He owns techcoil.com and hopes that whatever he had written and built so far had benefited people. All views expressed belongs to him and are not representative of the company that he works/worked for.

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How to Upload Files with Python’s requests Library

Python is supported by many libraries which simplify data transfer over HTTP. The requests library is one of the most popular Python packages as it’s heavily used in web scraping. It’s also popular for interacting with servers! The library makes it easy to upload data in a popular format like JSON, but also makes it easy to upload files as well.

In this tutorial, we will take a look at how to upload files using Python’s requests library. The article will start by covering the requests library and the post() function signature. Next, we will cover how to upload a single file using the requests package. Last but not least, we upload multiple files in one request.

Uploading a Single File with Python’s Requests Library

This tutorial covers how to send the files, we’re not concerned about how they’re created. To follow along, create three files called my_file.txt , my_file_2.txt and my_file_3.txt .

The first thing we need to do is install our the request library in our workspace. While not necessary, it’s recommended that you install libraries in a virtual environment:

Activate the virtual environment so that we would no longer impact the global Python installation:

Now let’s install the requests library with pip :

Create a new file called single_uploader.py which will store our code. In that file, let’s begin by importing the requests library:

Now we’re set up to upload a file! When uploading a file, we need to open the file and stream the content. After all, we can’t upload a file we don’t have access to. We’ll do this with the open() function.

The open() function accepts two parameters: the path of the file and the mode. The path of the file can be an absolute path or a relative path to where the script is being run. If you’re uploading a file in the same directory, you can just use the file’s name.

The second argument, mode, will take the «read binary» value which is represented by rb . This argument tells the computer that we want to open the file in the read mode, and we wish to consume the data of the file in a binary format:

test_file = open("my_file.txt", "rb") 

Note: it’s important to read the file in binary mode. The requests library typically determines the Content-Length header, which is a value in bytes. If the file is not read in bytes mode, the library may get an incorrect value for Content-Length , which would cause errors during file submission.

For this tutorial, we’ll make requests to the free httpbin service. This API allows developers to test their HTTP requests. Let’s create a variable that stores the URL we’ll post our files to:

test_url = "http://httpbin.org/post" 

We now have everything to make the request. We’ll use the post() method of the requests library to upload the file. We need two arguments to make this work: the URL of the server and files property. We’ll also save the response in a variable, write the following code:

test_response = requests.post(test_url, files = "form_field_name": test_file>) 

The files property takes a dictionary. The key is the name of the form field that accepts the file. The value is the bytes of the opened file you want to upload.

Normally to check if your post() method was successful we check the HTTP status code of the response. We can use the ok property of the response object, test_url . If it’s true, we’ll print out the response from the HTTP server, in this case, it will echo the request:

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if test_response.ok: print("Upload completed successfully!") print(test_response.text) else: print("Something went wrong!") 

Let’s try it out! In the terminal, execute your script with the python command:

Your output would be similar to this:

Upload completed successfully! < "args": <>, "data": "", "files": < "form_field_name": "This is my file\nI like my file\n" >, "form": <>, "headers": < "Accept": "*/*", "Accept-Encoding": "gzip, deflate", "Content-Length": "189", "Content-Type": "multipart/form-data; boundary=53bb41eb09d784cedc62d521121269f8", "Host": "httpbin.org", "User-Agent": "python-requests/2.25.0", "X-Amzn-Trace-Id": "Root=1-5fc3c190-5dea2c7633a02bcf5e654c2b" >, "json": null, "origin": "102.5.105.200", "url": "http://httpbin.org/post" > 

As a sanity check, you can verify the form_field_name value matches what’s in your file.

Uploading Multiple Files with Python’s requests Library

Uploading multiple files using requests is quite similar to a single file, with the major difference being our use of lists. Create a new file called multi_uploader.py and the following setup code:

import requests test_url = "http://httpbin.org/post" 

Now create a variable called test_files that’s a dictionary with multiple names and files:

test_files = < "test_file_1": open("my_file.txt", "rb"), "test_file_2": open("my_file_2.txt", "rb"), "test_file_3": open("my_file_3.txt", "rb") > 

Like before, the keys are the names of the form fields and the values are the files in bytes.

We can also create our files variables as a list of tuples. Each tuple contains the name of the form field accepting the file, followed by the file’s contents in bytes:

test_files = [("test_file_1", open("my_file.txt", "rb")), ("test_file_2", open("my_file_2.txt", "rb")), ("test_file_3", open("my_file_3.txt", "rb"))] 

Either works so choose whichever one you prefer!

Once the list of files is ready, you can send the request and check its response like before:

test_response = requests.post(test_url, files = test_files) if test_response.ok: print("Upload completed successfully!") print(test_response.text) else: print("Something went wrong!") 

Execute this script with the python command:

Upload completed successfully! < "args": <>, "data": "", "files": < "test_file_1": "This is my file\nI like my file\n", "test_file_2": "All your base are belong to us\n", "test_file_3": "It's-a me, Mario!\n" >, "form": <>, "headers": < "Accept": "*/*", "Accept-Encoding": "gzip, deflate", "Content-Length": "470", "Content-Type": "multipart/form-data; boundary=4111c551fb8c61fd14af07bd5df5bb76", "Host": "httpbin.org", "User-Agent": "python-requests/2.25.0", "X-Amzn-Trace-Id": "Root=1-5fc3c744-30404a8b186cf91c7d239034" >, "json": null, "origin": "102.5.105.200", "url": "http://httpbin.org/post" > 

Good job! You can upload single and multiple files with requests !

Conclusion

In this article, we learned how to upload files in Python using the requests library. Where it’s a single file or multiple files, only a few tweaks are needed with the post() method. We also verified our response to ensure that our uploads were successful.

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