The three Project Euler coding exercises that I selected are:

1. Problem 17:   Number letter counts
2. Problem 41:   Pandigital prime
3. Problem 47:   Distinct primes factors


For each problem, there is a 'run' module, a 'test' module
and an implementation module.  There is a doc comment for the
main() function in each 'run' module explaining how to run
that script and which arguments to supply. The 'test' modules
can simply be run. The code is written for the Python 3
environment.

The solutions to the problems are:

17:
Range:  [1,1000]   letter count:  21124

41:
The largest prime pandigital number is: 7652413

47:
For n: 4, first of 4 consecutive numbers with 4 distinct prime factors is: 134043