You might want to look into this: Functional Python Programming - Second Edition.

Let's talk about the type hints, shall we?

Most of the examples have had type hints added. This means running everything through mypy. And it also means running everything through doctest, as well.

More important than the technical …

The request was murky. It evolved over time to this:

Create a function file_record_selection(train.csv, 2, 100, train_2_100.csv)

First parameter: input file name (train.csv)

Second parameter: first record to include (2)

Third parameter: last record to include (100)

Fourth parameter: output file name (train_2_100.csv)

Fundamentally, this …

This. http://www.tomdalling.com/blog/software-design/fizzbuzz-in-too-much-detail/

And many other thoughts on overthinking fizz buzz. I'm going to overthink it, also. Why not?

This is a problem where the obvious unit test may not cover the cases properly. See https://projecteuler.net/problem=1 for a unit test case …

• http://www.agilebuddha.com/agile/agile-thinking-stop-starting-start-finishing/
• http://www.allaboutagile.com/stop-starting-start-finishing-unfinished-work-is-debt/
• http://www.leanagiletraining.com/key-problems/stop-starting-start-finishing/

Let's talk real-world functional programming. Disclosure: I'm a fan of functional programming in Python. (This: https://www.packtpub.com/application-development/functional-python-programming)

The usual culprits for functional programming are map(), filter(), generator functions, and the various comprehensions. This is very pleasant and can lead to succinct, expressive code.

The reduce operation …

https://slott56.github.io/five-kinds-of-python-functions Update: Steven Lott | The Five Kinds of Python Functions

See this: https://twitter.com/jakevdp/status/786920174595158018

The core expression is similar to this

y = (f(x) for x in L if f(x) is not None)

There are a lot of variations on the filter. The point is that the function appears twice in the above expression.

We …

Here's the question, lightly edited to remove the garbage. (Sometimes I'm charitable and call it "rambling". Today, I'm not feeling charitable about the garbage writing style filled with strange assumptions instead of questions.)

someone asked if you could have both a yield and a return in the same ... function/iterator …

I'm calling this the Composite Builder pattern. This may have other names, but I haven't seen them. It could simply be lack of research into prior art. I suspect this isn't very new. But I thought it was cool way to do some declarative Python programming.

Here's the concept.

class …