Project Euler Cli app

A simple cli app to show the problems from Project Euler.

Key learning points

  1. Building a cil app in python using Fire
  2. Making our app pip installable.

Modules used requests and BeautifulSoup. Code is straight forward, requests to get the html content and use BeautifulSoup to read the problem form the response which is in Div problem_content.

getProblem returns the problem and the url to the problem.

euler.py

import requests
import re
from bs4 import BeautifulSoup


class Euler:
    def __init__(self):
        self.baseUrl = 'https://projecteuler.net'
        self.problemUrl = self.baseUrl + '/problem=%s'

    def _generateProblemUrl(self, number):
        if number == None or number == 0 or number == '0':
            return None

        return self.problemUrl % number

    def _getUrlContent(self, url):
        if url == None:
            return None

        r = requests.get(url)
        if r.status_code != requests.codes.ok:
            return None
        return r.content

    def _getProblemFromHtml(self, htmlContent):
        if htmlContent in [None, '']:
            return None

        soup = BeautifulSoup(htmlContent, 'html.parser')

        probNotAvail = soup.findAll(text=re.compile('Problem not accessible'))
        if len(probNotAvail) > 0:
            return None

        try:
            ps = soup.select("div p")
            s = [p.getText().replace('\n', '') for p in ps]
            s = ' '.join(s)
        except:
            return None

        s = s if s != '' else None

        return s

    def getProblem(self, number=None):
        url = self._generateProblemUrl(number)
        if url is None:
            return None, None

        content = self._getUrlContent(url)
        if content is None:
            return url, None

        return url, self._getProblemFromHtml(content)

Folder structure


(euler) ➜ (NMUDIVAR-M-422V) euler git:(master) ✗ tree
.
├── README.md
├── euler
│   ├── __init__.py
│   ├── __main__.py
│   ├── euler.py
│   └── test_euler.py
├── euler.egg-info
│   ├── PKG-INFO
│   ├── SOURCES.txt
│   ├── dependency_links.txt
│   ├── entry_points.txt
│   └── top_level.txt
├── makefile
├── requirements.txt
└── setup.py

Setup.py To make the app pip installable, we need to have setup.py. All we do in this is import the setup method from setuptools and calling it with few arguments. Key argument here is entry_points. Using this we specify which runnable application will be invoked. We set it up as euler.__main__:main .

from setuptools import setup

setup(
    name='euler',
    version='0.1.0',
    packages=['euler'],
    entry_points={'console_scripts': ['euler = euler.__main__:main']})

Installing the app using pip during development

Easiest way to install and uninstall your Python Cli app is to use pip. This is as simple as executing below command.

pip3 install -e .

We can put this in make file so that we don’t have to type out entire command.

install:
	pip3 install -e .

Source code for this app is at GitHub - Naren-m/euler: Terminal app to access project Euler problems in terminal

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