11 postures downloaded using Python, each more advanced than the last

Below you will learn how to overcome various challenges you may encounter, such as downloading redirected files, downloading large files, completing a multi-threaded download, and other strategies.

1. Using requests

You can use the requests module to download files from a URL.

Consider the following code:

You simply get the URL using the get method of the requests module and store the result into a variable called "myfile" middle. Then, write the contents of this variable to the file.

2. Using wget

#You can also use Python’s wget module to download files from a URL. You can install the wget module using pip by following the command:

Consider the following code, which we will use to download the logo image for Python.

In this code, the URL and path (where the image will be stored) are passed to the download method of the wget module.

3. Downloading Redirected Files

In this section, you will learn how to use requests to download a file from a URL that will be redirected to another with a .pdf The URL of the file. The URL looks like this:

To download this pdf file, use the following code:

In this paragraph In the code, the first step we specify is the URL. Then, we use the get method of the request module to get the URL. In the get method, we set allow_redirects to True, which will allow redirections in the URL and the redirected content will be assigned to the variable myfile. In addition, search the backend of the public account for top architects to reply "Interview Status" to get a surprise gift package.

Finally, we open a file to write the obtained content.

4. Download large files in chunks

Consider the following code:

First, we use the get of the requests module as before method, but this time, we will set the stream property to True.

Next, we create a file named PythonBook.pdf in the current working directory and open it for writing.

Then, we specify the chunk size to be downloaded each time. We've set it to 1024 bytes, then iterated through each chunk and written those chunks to the file until the end of the chunk.

Isn't it beautiful? Don't worry, we will display a progress bar of the download process later.

5. Download multiple files (parallel/batch download)

To download multiple files at the same time, please import the following module:

We imported the os and time modules to check how long it takes to download the file. The ThreadPool module allows you to run multiple threads or processes using a pool.

Let's create a simple function that sends the response in chunks to a file:

This URL is a two-dimensional array that specifies your The path and URL of the page to download.

Just like we did in the previous section, we pass this URL to requests.get. Finally, we open the file (the path specified in the URL) and write the page content.

Now, we can call this function for each URL individually, or we can call this function for all URLs at the same time. Let’s call this function for each URL individually in a for loop, paying attention to the timer:

Now, replace the for loop with the following lines of code:

Run the script.

6. Download using the progress bar

The progress bar is a UI component of the clint module. Enter the following command to install the clint module:

Consider the following code:

In this code, we first The requests module is imported, and then we import the progress component from clint.textui. The only difference is in the for loop. When writing content to a file, we use the bar method of the progress bar module.

7. Use urllib to download a web page

In this section, we will use urllib to download a web page.

The urllib library is Python’s standard library, so you don’t need to install it.

The following lines of code can easily download a web page:

Here specify what you want to save the file for and the URL of where you want to store it .

In this code, we use the urlretrieve method and pass the URL of the file, and the path to save the file. The file extension will be .html.

8. Downloading through a proxy

If you need to use a proxy to download your files, you can use the ProxyHandler of the urllib module. Please look at the following code:

In this code, we create the proxy object and open the proxy by calling urllib's build_opener method and pass in the proxy object . Then we create a request to get the page.

In addition, you can also use the requests module as described in the official documentation:

You only need to import the requests module and create your proxy object. Then, you can get the file.

9. Using urllib3

urllib3 is an improved version of the urllib module. You can download and install it using pip:

We will use urllib3 to get a web page and store it in a text file.

Import the following modules:

When processing files, we use the shutil module.

Now, we initialize the URL string variable like this:

Then, we use urllib3’s PoolManager, which keeps track of the necessary connection pools.

Create a file:

Finally, we send a GET request to get the URL and open a file, Then write the response to the file:

10. Download files from S3 using Boto3

To download files from Amazon S3, you can use the Python boto3 module .

Before you begin, you need to install the awscli module using pip:

For AWS configuration, run the following command:

Now, enter your details by pressing the following command:

To download files from Amazon S3, you need to import boto3 and botocore. Boto3 is an Amazon SDK that allows Python to access Amazon web services (such as S3). Botocore provides a command line service for interacting with Amazon web services.

Botocore comes with awscli. To install boto3, run the following command:

Now, import these two modules:

From Amazon When downloading a file, we need three parameters:

• Bucket name
• The name of the file you need to download
• The name of the file after downloading

Initialize variables:

Now, we initialize a variable to use the session’s resources. To do this, we will call boto3's resource() method and pass in the service, which is s3:

Finally, use the download_file method to download the file and pass in the variable:

11. Using asyncio

The asyncio module is mainly used to handle system events. It works around an event loop that waits for an event to occur and then reacts to that event. The reaction can be to call another function. This process is called event processing. The asyncio module uses coroutines for event handling.

To use asyncio event handling and coroutine functionality, we will import the asyncio module:

Now, define the asyncio coroutine method like this:

The keyword async indicates that this is a native asyncio coroutine. Inside the coroutine, we have an await keyword, which returns a specific value. We can also use return keyword.

Now, let’s create a piece of code to download a file from a website using a coroutine:

In this code, we create an asynchronous coroutine function , which will download our file and return a message.

Then, we use another asynchronous coroutine to call main_func, which will wait for the URL and form all the URLs into a queue. asyncio's wait function waits for the coroutine to complete.

Now, in order to start the coroutine, we have to put the coroutine into the event loop using asyncio's get_event_loop() method, and finally, we execute the event loop using asyncio's run_until_complete() method.

Downloading files using Python is fun. Hope this tutorial is useful to you!

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