Thanks to Joel and Alan for replying. On 24 January 2016 at 22:08, Alan Gauld <alan.ga...@btinternet.com> wrote:
> On 24/01/16 19:42, STF wrote: > > > Let's see the following instructions: > > -------- > > if condition_A: > > instruction_1 > > instruction_2 > > if condition_B: > > instruction_3 > > instruction_4 > > instruction_5 > > else: > > instruction_6 > > -------- > > > > * How to make Pythom understand that instruction_4 is a part of > condition_B > > if-clause but not a direct instruction of condition_A if-clause? > > You've done it above by the indentation. > It's a total fluke. I put the indentation like this to *visually* help myself understand what I was going to write. In the Python tutorial that I was using, the author only told us to use indentation, without emphasizing on the size of it. > > to make Python understand that instruction_5 is outside of condition_B > > if-clause? Just by the number of white spaces in front of every > > instruction?? > > Yes, the indent level tells Python where the instruction should be. > > > * How to make Python understand that "else" belongs to the first > > condition_A if-clause, not to the immediate condition_B if-clause? > > Again you've done it already, just use the indent level. > > > * Suppose I put four white spaces in front of instruction_1, and then > "tab > > key" in front of instruction_2, would this break things? > > In Python 2 things are a wee bit flexible but in Python 3 less so. > But in general avoid mixing them, stick to spaces. Most Python > programmers set their text editor/IDE to convert tabs to > spaces(usually 4) > > > most intelligent text editors would insert automatically a tab in place > of > > 4 white spaces after we press Enter on a line with 4 leading white > spaces. > > Most can also be configured not to use tabs at all and > for Python that's better. Tell us your editor and somebody > can probably advise on optimum settings. > As I'm a newbie, I'm mostly using Python IDLE but sometimes I would use Programmer's Notepad. > > > * Do I really need to keep the consistency of 4 white spaces? Not one > more > > or one less? > > No you can have as many or as few as you like in your own code, > just be consistent. 4 just happens to be esy to read. And its > the standard for library code so if you want to write some code > for the standard library you will need to use 4 spaces. In > the interpreter (>>>) I often only use 2 just to save typing. > But for production code I stick with 4 - not a problem since > the editor(vim) does most of the work for me. > Let me ask an alternative question. Suppose I have something like this: ---- if condition_C: instruction_10 instruction_11 instruction_12 ---- There are 4 spaces in front of instruction_10, 3 spaces in front of instruction_11 and 5 spaces in front of instruction_12. What would happen to instruction_11 and instruction_12? Would Python ignore them? Or would they be considered instructions outside the if-clause? Thanks again. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor