Tips

Use case Sometimes you just want to capture the first (or last) event of something. Let’s say, you have a list of clients and want to capture their first purchase. This is useful if you want a list of new paying customers. Dataset We’re thinking about customers here, so let’s get the Online Retail Dataset from the UCI Machine Learning Repository. We can download this dataset directly using Pandas. >>> import pandas as pd >>> customers = pd....

Logs play a very important role throughout the entire life cycle of an application development as well as troubleshooting and replicating bugs on production that could lead to service interruption and harm our user’s experience. A few months ago, I went on a journey for finding a tool that will allow me to improve logs visibility and to take action as quickly as possible, and of course with a minimum amount of effort and server requirements....

Sometimes you just want to save a dictionary, a list, a string, or anything into a file so you can use it later. This can be easily achieved with the module Pickle. Warning: The pickle module is not secure against erroneous or maliciously constructed data. Never unpickle data received from an untrusted or unauthenticated source. — Pickle Documentation What is Pickle Pickle is a module in Python that can be implemented to serialize or de-serialize a Python object, meaning that it can be used to save an object into a file; Just have in mind that this is not the same as saving a configuration file, there are other data structures that we can use to achieve that task such as JSON, CSV, YAML/TOML, etc....

Today I was facing a problem, I didn’t know how to change Flask root directory. Flask by default look for templates and static files under the root directory (/), how can we change that? Changing the root path Here’s my directory structure: . ├── api_files │ ├── static │ │ └── style.css │ └── templates │ └── index.html ├── api.py ├── Pipfile └── Pipfile.lock 3 directories, 5 files I want Flask to be able to process the folders static and templates inside the api_files folder, my main Flask app is api....

You don’t need a bunch of if’s and else if’s to create an array of directories in python, just the good ol’ makedirs. Create an array of directories To create an array of directories you must import the package os and import the method makedirs >>> from os import makedirs >>> makedirs('1/2/3/4/5') You’ll see now that your directories are created correctly, let’s run the command tree outside of python to see if they’re were actually created....

There’s a great library added in Python 3.5 that lets you return a list of filenames and folders called glob, here’s how to use it. Return files and folders in current folder. >>> glob('**') ['scaffolds', 'node_modules', 'yarn.lock', '_config.yml', 'source', 'db.json', 'themes', 'package.json', 'package-lock.json'] Return files and folders recursively >>> glob('**', recursive=True) ['scaffolds', 'scaffolds/post.md', 'scaffolds/page.md', 'scaffolds/draft.md', 'node_modules', '...'] Return only specific type of files recursively >>> glob('*.json', recursive=True) ['db.json', 'package.json', 'package-lock.json'] non-recursively >>> glob('**/*....

I encourage developers to see the value of unit testing; I urge them to get into the habit of writing structured tests alongside their code. — CodingHorror I was reading about Unit Testing and found a blog entry in CodingHorror called I Pity The Fool Who Doesn’t Write Unit Tests, and guess what, he’s right. Sadly, I’ve encountered a lot of people who doesn’t write tests for their code, and have a CI System (Travis, Jenkins, Gitlab, etc....

To get the filesize of a download is really easy, servers usually provide a Content-Length in its header response that let us know how heavy is the content we are requesting. We can find out this content length opening our shell and requesting a HEAD response in linux: As you can see, our content length is display in bytes. Let’s try to get this response with Requests Display Content-Length with Requests Let’s use an image from httpbin....

Pyenv is an excellent tool to have in your tool-set, it manages Python versions much like rbenv for Ruby, in fact it was forked from it. pyenv lets you easily switch between multiple versions of Python. It’s simple, unobtrusive, and follows the UNIX tradition of single-purpose tools that do one thing well. Installation The automatic installer provided in GitHub will take care of everything so you don’t have to worry about configuring anything....

What is pipenv Essentially Pipenv is pip + virtualenv and it’s a match made in heaven. It manages dependencies, required python versions (if pyenv is available), generates pipfiles which is more reliable than a requirements.txt file and it generates a virtual environment so you don’t screw other environments and its requirements. It automatically creates and manages a virtualenv for your projects, as well as adds/removes packages from your Pipfile as you install/uninstall packages....