python requests iter_content

Python requests iter_content

If you are working with Python and making requests to a website, you may come across a situation where you need to download large files. This can be a problem because if you use the usual requests.get() function, it will download the entire file into memory before writing it to disk. This can cause performance issues and even crash your program if the file is too large.

That's where iter_content() comes in. This function allows you to download large files in small chunks, which is much more efficient and doesn't take up as much memory.

Syntax

The syntax for using iter_content() is:

import requests

response = requests.get(url, stream=True)

with open(filename, 'wb') as f:
    for chunk in response.iter_content(chunk_size=1024):
        if chunk:
            f.write(chunk)

Explanation

  • import requests: Import the requests library.
  • response = requests.get(url, stream=True): Make a GET request to the specified URL with streaming enabled. This will cause the response to be downloaded in chunks rather than all at once.
  • with open(filename, 'wb') as f:: Open the file in binary write mode.
  • for chunk in response.iter_content(chunk_size=1024):: Iterate over the content of the response in chunks of 1024 bytes.
  • if chunk:: Check if the chunk is not empty.
  • f.write(chunk): Write the chunk to the file.

By default, iter_content() downloads chunks of 1 byte. You can specify a larger chunk size by passing a value to the chunk_size parameter.

Another way to use iter_content() is to pass the iterator directly to the write() method of a file object. This eliminates the need for the if statement in the code above:

import requests

response = requests.get(url, stream=True)

with open(filename, 'wb') as f:
    f.write(response.iter_content(chunk_size=1024))

This code downloads the response in chunks of 1024 bytes and writes them directly to the file.

Overall, iter_content() is a powerful tool for downloading large files in Python. It allows you to conserve memory and improve performance by downloading files in small chunks.