How to create and delete a folder in Python using Pathlib?

Abdallah Yashir — Fri, 21 Jan 2022 10:27:59 +0000

Folder Manipulation

These are the codes that I'm implementing for creating and deleting a folder.

What I like with Python for automating stuff is the language simplicity. With a few lines of code, you can do amazing things. I can also use PowerShell scripts, but I like writing cross-platform scripts or applications wherever possible.

This time I'm not using a class but calling the functions directly, as I see the case in many examples on YouTube tutorials. Perhaps that's more efficient for quick and dirty ad hoc projects.

Box

For the name, I choose Box as a synonym to file because it might be confusing. I'm already using files classes or modules from libraries such as pathlib. So this is a good way to keep things simple with the naming.

The aim is this code is to:

create a "posts" folder
place the number of transformed posts
zip the folder
delete the "posts" folder

I've yet to test the whole flow due to a lack of time.

When dealing with OS and external operations such as API calls, I like using try except in any language I'm coding with.

The reason is so that I can better track these types of errors and plan a countermeasure for them, such as retrying.

This makes the programs more resilient. On the other side, I also want in most situations that the script completely stops. For instance, if there is no Ghost JSON file in my current side project, there is no point in continuing.

Codes

box.py

from pathlib import Path

def folder_exists(folder_name):
    return Path(folder_name).is_dir()

def create_folder(folder):
    try:
        if not folder_exists(folder):
            Path(folder).mkdir(parents=True, exist_ok=True)
    except OSError as e:
        print(f"Error: {e.strerror}")

def delete_folder(folder):
    try:
        if folder_exists(folder):
            Path(folder).rmdir()
    except OSError as e:
        print(f"Error: {e.strerror}")

def sync_folder(folder):
    delete_folder(folder)
    create_folder(folder)

def zipFolder():
    return None

main.py

folder_name = "posts"
box.sync_folder(folder_name)

There are two ways of writing codes in my opinion:

Typing the flow in a single function and then refactoring into relevant classes/methods/functions (if needed)
creating the classes/methods/functions first (you can even write their unit tests) and then stitching everything together

In this case, I choose the second variation as it's easy to progress with the project with one quick file at a time. I also like the abstraction.

I would nevertheless recommend, especially if you're still learning the language or the programming stack, to do it as simple as possible. This is how I usually proceed when working on Java or C# for enterprise systems.

This is the whole repo.

How I try to automate a repetitive task of extracting a token from a string

Abdallah Yashir — Fri, 14 Jan 2022 13:19:59 +0000

Use case

I'm using Swagger to load mock values into a system.

To do that, I need to authenticate using a bearer token from another system that also uses swagger.

I also need to do at least one request to get the curl request that contains the token.

Once done, I copy and paste it on a notepad before choosing only the string after the bearer token. Here's an example:

Source:

curl -X POST "http-some-api" -H "accept: */*" -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"

Target:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

I do this several times throughout the day when working on this project.

Here's the project GitHub repo.

If you want more information:

what is a bearer token? The bearer token is a cryptic string, usually generated by the server in response to a login request. The client must send this token in the Authorization header when making requests to protected resources: Authorization: Bearer [1]

how to generate one? [2]

Automate

I begin thinking on how can I spend 30 mins to 1 hour automating at least getting the exact token I need.

My use case is that once I copy the curl string, I just click on the script, and it adds the token in the clipboard.

I then just need to paste it into the swagger target auth input.

Technology

As usual I'm using Python which I think it's one of the best programming languages for automating scripts.

I use the pyperclip package to read from and write to the clipboard.

Then pyinstaller to generate the exe file.

I also use pipreqs to manage dependencies.

I've also copied pasted the gitignore from:

https://github.com/github/gitignore/blob/main/Python.gitignore

Project

I use PyCharm community edition to create the project.

I empty the default main.py file.

I break down each function to do only one thing.

import pyperclip


def copy_from_clipboard():
    return pyperclip.waitForPaste()
    # return pyperclip.waitForNewPaste()


def copy_to_clipboard(content):
    pyperclip.copy(content)


def extract_bearer_token(content):
    # check if the string is present otherwise do nothing
    if "Authorization: Bearer " in content:
        # ignore the header parts and only take the token
        header, token = content.split("Authorization: Bearer ")
        # strip any leading and trailing whitespace
        return token[0:len(token) - 1].strip()
    return None


if __name__ == '__main__':
    content = copy_from_clipboard()
    token = extract_bearer_token(content)
    copy_to_clipboard(token)

Moreover, I still can separate the detection of the bearer token and extracting the specific string.

This is recommended as it's easier to unit test.

Improvements

In terms of User Experience (UX), I also need to manually click on the exe file each time I want to get the token.

A simple improvement is just launching the script once and it will automatically listen to any clipboard event.

From that it will detect and extract as appropriate.

Conclusion

I believe automating tasks, especially the repetitive and boring ones, can help free our time in the long run, so that we can learn new things and help more people.

You can ask me any question on Twitter.

References

[1] - https://swagger.io/docs/specification/authentication/bearer-authentication/#:~:text=The%20bearer%20token%20is%20a,Authorization%3A%20Bearer

[2] - https://jwt.io/

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