Python-based Project Euler command line tool.
EulerPy is a command line tool designed to streamline the process of solving Project Euler problems using Python. The package focuses on two main tasks: firstly, to create Python “template” files with a docstring containing the text of a Project Euler problem for ease-of-reference, and secondly, to check whether a problem has been solved correctly.
EulerPy can be installed (and updated) from PyPI using pip:
$ pip install --upgrade EulerPy
Conversely, it can be uninstalled using pip as well.
$ pip uninstall EulerPy
First, you’ll want to cd to the directory where your Project Euler files are being stored.
$ mkdir ~/project-euler $ cd ~/project-euler
At this point, you’ll probably want to run the euler command, which will prompt to create 001.py, a file containing the text to Project Euler problem #1 as its docstring.
$ euler No Project Euler files found in the current directory. Generate file for problem 1? [Y/n]: Y Successfully created "001.py". $ cat 001.py """ Project Euler Problem 1 ======================= If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23. Find the sum of all the multiples of 3 or 5 below 1000. """
At this point, you can open up your editor of choice and code up a solution to the problem, making sure to print() the output. Once you feel that you’ve solved the problem, run the euler command again to verify your solution is correct. If the answer is correct, the solution will be printed in green and the script will ask to generate the next problem file. If incorrect, the solution will be printed in red instead. Additionally, the time elapsed during the solution-checking process will also be printed.
$ euler Checking "001.py" against solution: [no output] # (output in red) $ echo print 42 >> 001.py $ euler Checking "001.py" against solution: 42 # (output in green) Generate file for problem 2? [Y/n]: Y Successfully created "002.py".
EulerPy also has a few command line options that act as different commands (use euler --help to see a summary of all the options).
--cheat / -c
The --cheat option will print the answer to a problem after prompting the user to ensure that they want to see it. If no problem argument is given, it will print the answer to the problem that they are currently working on.
$ euler --cheat View answer to problem 2? [y/N]: Y The answer to problem 2 is <redacted>. $ euler --cheat 100 View answer to problem 100? [y/N]: Y The answer to problem 100 is <redacted>.
--generate / -g
The --generate option will create a Python file for the given problem number. If no problem number is given, it will overwrite the most recent problem with a file containing only the problem docstring (after prompting the user).
$ euler --generate Generate file for problem 2? [Y/n]: Y "002.py" already exists. Overwrite? [y/N]: Successfully created "002.py". $ euler --generate 5 Generate file for problem 5? [Y/n]: n Aborted!
euler <problem> is equivalent to euler --generate <problem> if the file does not exist.
$ cat 005.py cat: 005.py: No such file or directory $ euler 5 Generate file for problem 5? [Y/n]: n Aborted!
--preview / -p
The --preview option will print the text of a given problem to the terminal; if no problem number is given, it will print the next problem instead.
$ euler --preview Project Euler Problem 3 The prime factors of 13195 are 5, 7, 13 and 29. What is the largest prime factor of the number 600851475143? $ euler --preview 5 Project Euler Problem 5 2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder. What is the smallest number that is evenly divisible by all of the numbers from 1 to 20?
--skip / -s
The --skip option will prompt the user to “skip” to the next problem. As of EulerPy v1.1, it will also append a “skipped” suffix to the skipped problem file.
$ euler --skip Current problem is problem 2. Generate file for problem 3? [y/N]: Y Successfully created "003.py". Renamed "002.py" to "002-skipped.py".
--verify / -v
The --verify option will check whether a given problem file outputs the correct solution to the problem. If no problem number is given, it will check the current problem.
$ euler --verify Checking "003.py" against solution: [no output] # (output in red) $ euler --verify 1 Checking "001.py" against solution: <redacted> # (output in green)
As of EulerPy v1.1, verifying a skipped problem file will remove the “skipped” suffix from its filename.
$ euler --verify 1 Checking "001-skipped.py" against solution: <redcated> Renamed "001-skipped.py" to "001.py".
euler <problem> is equivalent to euler --verify <problem> if the file does exist.
$ cat 001.py """ Project Euler Problem 1 ======================= If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23. Find the sum of all the multiples of 3 or 5 below 1000. """ $ euler 1 Checking "001.py" against solution: <redacted>
The --verify-all option was added in EulerPy v1.1. It essentially runs --verify on all the problem files it can find in the current directory, but also prints an overview of all of the problems in the directory. Note that if the verification encounters a KeyboardInterrupt exception, it will skip the verification of that specific file. This allows for the ability to skip verifying some files but not others, in the case that some solutions are taking too long to compute.
$ euler --verify-all Checking "001.py" against solution: <redacted> Checking "002.py" against solution: [no output] --------------------------------------------------------------- C = correct, I = incorrect, E = error, S = skipped, . = missing Problems 001-020: C I . . . . . . . . . . . . . . . . . .
This option should be run after upgrading to v1.1 from EulerPy v1.0, as it will automatically rename any problems that have been skipped using --skip, making them easy to distinguish from those that have been correctly solved.
See this blog post for insight into the development process.
EulerPy uses click as a dependency for its CLI functionality.
EulerPy is licensed under the MIT License.