In this lesson, Mr Shaw introduces the idea of creating one’s own functions. Fortunately, I have plenty of experience with this and this exercise fazed me not much at all. It takes a moment to get my bearings considering what gets passed through to the defined functions, but it’s really not bad overall. I do see the difference again between Pythons 3.3 and 2.7 again, though, in the way that the arguments are inserted in a print statement via the %r rather than just exiting briefly out of what is being printed and just throwing the variable.
3.3 (what I am used to):
print(“The variable goes here:”, variablename,”.”)
print “The variable goes here: %r.” %variablename
Passing the parameters from the command line as arguments into the defined functions seems to make sense! **(Edit: nothing is passed from the command line to run the program, here. The arguments are defined within the program, not without.) Since a function just does whatever you tell it to (I suppose the same could be said of literally anything you punch into a future program), its structure and formatting does not elude me, especially since we made lots of them when I was knee-deep in 3.3.
And how exciting! He has a big red warning, “don’t worry if you are confused,” well, I am not! Yay! I know I will keep having other troubles down the line, but this one is pretty ok!
The Common Student Questions area advises me to try to break if it I seem bored 🙂 so that is what I did! I passed an argument into a function without using it in that newly defined function, and it wigged out – perfect! I don’t think 3.3 cared if you used the parameter/arg/var passed in, but 2.7 does, and that is sensible and easy to synthesize.
Ok! I started this lesson a few weeks ago. Each week I work on programming for just a few hours at PyLadies PDX and go about my business the rest of the week, sometimes coming back to whatever I’m working on during the week, but typically I have enough that keeps me occupied and away from programming Sunday through Friday.
This lesson has been difficult to get through all of the Study Drills of, as I’m having a hard time reducing the code by much, other than just taking out the print statements. I don’t see the need to count the length of the .txt file or to run the EXISTS function, but I also don’t see a need to omit them. He leaves a hint in the Common Student Questions that you ; can ; make ; a ; statement ; one ; line if you want to, but… I have never used semicolons in Python, just C++ (via a few chapters of Michael Dawson’s wonderful book), and I fail to see the good of obfuscating one’s code for sake of just making it one line, as Mr Shaw suggests he can do, I suppose, by separating the lines with a semicolon rather than a return, if that is even possible.
I am also still getting the hang of ARGV, the function that permits me to insert files into the program from the command line. It is not too complicated, it is just not something that I have seen before, and flub it up still on occasion. All the same I see its usefulness and look forward to being able to use it more effectively.
So I shall move on!
Being nominally familiar with Python, these first lessons went by in a breeze. The biggest hiccup (if you can call it that) was going through the Command Line Crash Course, also written by Zed Shaw (the gent who wrote LPTHW). It was enormously helpful but took me approximately a week to get to the level of knowledge that I wanted. I did not finish it as I was very impatient to get back to lovey-woo-woo python, but my facility with the command line is prrrrobably as good as I’ll need it for the time being.
Several lessons went by per sitting, working things out with very satisfactory comprehension, until I got to Lesson 13! Lessons 13, 14, 15, and 16 have all begun to tax me much more than previous lessons, which is to be expected.
It’s odd, I can do all kinds of looping & sub-looping and data structures (with some effort) in Python 3.3, but in 2.7 my knowledge is developing completely laterally to that kind of capability. What that really means, at least to me, is that I am actually gaining new knowledge rather than just learning the formatting for while loops with 2.7’s idiosyncrasies and moving on. It is great.
One complaint that I have heard regarding Mr Shaw’s tone is that he is a bit short and a bit arrogant in that way that programmers are known to be. If this description is too vague for you, then you fortunately have not been over-exposed to this kind of attitude. I am a bit refreshed by his tone, however, because I find that he is right, and learning from someone with that kind of confidence in what he or she is teaching is totally instrumental in my absorption of the material, personally. Besides, I like a little sass, and I like a little old-school-style coding education.
Ok! Enough prelude! At this time, I’m at lesson 17, so let’s move on to that! “Next entry, please!” is what I know you are saying!