About Rick van Hattem (Wolph)


My name is Rick van Hattem (nickname: Wolph, hence the domain name). For the last couple of years I have been working on a couple of startups, more recently I have decided to take a step back and do some consultancy to do research for my next startup.

My main areas of expertise are currently:

  • Scaling systems with large amounts of data and/or users
  • PostgreSQL
  • Python
  • Django

Mastering Python, the Python 3.5 and above book I wrote for experienced Python programmers to improve their skills:

For more info about me and my projects:

The things that interest me are mainly the big/difficult problems, the more difficult a problem is the more fun I’ll have solving it.

Bookmark and Share

4 Responses to “About Rick van Hattem (Wolph)”

  1. Anshu Kumar | 2016-07-18 at 08:42:01 #

    Hi Rick,

    I was going through your wonderful book, mastering python.

    I think when you are explaing “Beautiful is better than ugly” in Chapter-2

    filter_modulo = lambda i, m: [i[j] for i in range(len(i))
    if i[j] % m]

    It looks like a nit, for loop should iterated with variable “j”.

    Thank You,

    • Rick van Hattem | 2016-07-18 at 09:07:23 #

      Hi Anshu,

      You are indeed correct. While rewriting that code sample (I switched from i and j to items and modulo) it seems I have forgotten to modify that sample as well.

      The sample should be either:

      filter_modulo = lambda i, m: [i[j] for j in range(len(i)) if i[j] % m]


      filter_modulo = lambda items, modulo: [items[i] for i in range(len(items))
                                             if items[i] % modulo]

      Thanks for letting me know. I’ve added the correct code samples to the repository: https://github.com/mastering-python/code/commit/f7ec4fc2480614ea8369f7d27a99b22046e2a780

      Best, Rick

  2. Mark London | 2017-02-25 at 02:58:48 #

    Can your “Django Tags Input” module be used in front end user forms in django, rather than the admin page? K.s

Leave a Reply