I'm surprised no one has mentioned Peter Norvig yet. http://norvig.com/21-days.html http://norvig.com/21-days.html From your comments, I kind of get that you

I'm surprised no one has mentioned Peter Norvig yet. http://norvig.com/21-days.html http://norvig.com/21-days.html From your comments, I kind of get that you want to be a real good programmer, and part of being a good programmer is to understand the different way you can wire bit and pieces together in the many different languages. I had a similar experience as you in that I went from C->C++->Java->Javascript->Scheme->SML->Python. I can definitely tell you that learning Scheme and SML first helped me tremendously in understanding dynamic languages in general. In more concrete terms, understand typing rules has helped me how to debug a program when I mess up in Python. For example, in SML, I can completely omit type annotations and the interpreter will infer the right type for me at parse-time, and that each function or statement must only return 1 type. In dynamic languages such as Python, you can still do what you can do in SML or Haskell, but the runtime system makes no guarantee that your program as it is written is type-safe when the interpreter parses all your source files. Type checking is done at execution, when the code path in question is exercised. However, if you THINK about how the types are infered in SML when you write in Python, you generally will not run into TypeErrors. The same goes for functions that return different types. To prevent tripping up with these functions, just apply what you've learned in Haskell or SML when you are debugging library functions that do this, and avoid writing functions that return different types.