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Improve this questionC++ is my first language, and as such I'm used to whitespace being ignored. However, I've been toying around with Python, and I don't find it too hard to get used to the whitespace rules. It seems, however, that a lot of programmers on the Internet can't get past the whitespace rules. From what I've seen, peoples' C++ programs tend to be formatted very consistently with respect to whitespace (or else it's pretty hard to read), so why do some people have such a problem with whitespace-based languages like Python开发者_StackOverflow中文版?
It violates the Principle of Least Astonishment, because we have it ingrained in ourselves (whether for good or bad) that whitespace Does Not Matter in a programming language. Whitespace is one of those issues that has been left up to personal style.
I still have bad memories back from being a student of learning the hard way that 8 spaces is not equivalent to a tab in a Makefile... Ah, the sleep I lost...
The only valid reason I have come across is that refactoring using cut-and-paste (not copy) without refactoring tools (or syntax-aware cut-andpaste), can end up changing semantics if an easy mistake is made.
There are several different types of whitespace (spaces, tabs, weird unicode characters, carriage returns, line breaks, etc.), they aren't necessarily visually distinct, and languages and editors may treat them capriciously. This isn't an argument against well-designed whitespace semantics, but many people are against all forms of it simply because of the possibility of poor design.
People hate it because it violates common sense. Not a single one of the replies I have read here decided that it was ok to simply forgo periods and other punctuations. In fact the grammar has been very good. If the nonsense about indentation actually carrying the meaning were true we would all just forget about using punctuations entirely.
No one learned that newlines terminate a sentence in a horizontal language like English, instead we learned to infer when a sentence ended regardless of whether or not the punctuation was present or not.
The same is true for programming languages, especially for those of us who started out with a programming language that did use explicit block termination. You learn to infer where a block starts and stops over time, it does not mean that the spacing did that for you, the semantics of the language itself did.
Most literate people would have no problem understanding posts without punctuations. Having to rely on what is a representation of the absence of a character is not a good idea. Do any of you count from zero when you make your to-do list?
Alright, this is a very narrow perspective, but I haven't seen it mentioned elsewhere: keeping track of white space is a hassle if you are trying to autogenerate a script.
When I first encountered Python, I don't remember the details, but I had developed a Windows tool with a GUI that allowed novice users to configure several settings, and then press OK. The output of the tool was a script, which the user could copy to a Unix machine, and then execute it there to do something or other that was too complicated or tedious for them to do manually. Since nobody maintained the generated scripts, there was no reason they needed to look nice. So, keeping track of indentation seemed like an unnecessary burden from that perspective.
For most purposes, though, I find that Python is much easier than any other language.
Perhaps your C++ background (and thus who your peers are) is clouding your perception of this (ie selective sampling) but in my experience the reaction to Python's "white space is intent" meme is anywhere from ambivalent to they absolutely love it. The reason a lot of people love it is that it forces people to format their code.
I can't say I've ever met anyone who "hates" it because hating it is much like hating the idea of well-formatted code.
Edit: let me put this in some perspective.
In the Java world there are two main methods of packaging and deploying Web apps: Ant and Maven.
Ant is basically an XML-based Make facility that has tasks for the common things you do. It's a blank slate, which is powerful, but it also means you have to write a lot of common things yourself and every installation is free to do things slightly differently. All of this is well-intentioned but can make it hard to figure out someone's Ant scripts.
Maven is far more fully features. It has archetypes, which are basically project types. Depending on which archetype(s) you use, you won't have to write any tasks to start, stop, clean, build, etc but you will have a mandated directory structure, which is quite deep.
The advantage of that is if you've seen one Maven Web app you've seen them all. You know the commands. You know the structure. That's extremely useful.
But you have people who absolutely hate Maven and I think it comes down to this: they don't like giving up control, even when it's ultimately in their interest to do so. Also, you'll find a certain brand of person who thinks that their use case is a justifiable exception. You see this personality trait a lot. For example, I think an old Joel post mentioned a story where someone wanted to use "enter" to go from the username to password form fields even though the convention was that enter executed the default action (usually "OK") so they had to write a custom dialog class for Windows for this.
Basically some people just don't like being told what to do and others are completely obstinate in their belief that they're right even when all evidence points to the contrary.
This probably explains why some supposedly hate Python's white space: they don't like being told how to format their code. They like the freedom of C/C++.
Because change is scary. And maybe, among certain developers, there are some faint memories of languages with capricious rules about whitespacing that were hard to remember and arbitrary, meant more for compiler convenience than expressiveness.
Most likely, not giving whitespace-significance a fair shake before dismissing it is the real reason. Ask someone to fix a bug in a reasonably complex but well-written Python program, then ask them to go fix a bug in a 20 year old system in C, VB or Cobol and ask them which they prefer.
As for me, I have as much trouble with whitespace in Python or Boo as I have with parentheses in Lisp. Which is to say, none.
They will have to get used to it. Initially I had a problem my self trying to read some examples but after using language for some time I started liking it.
I believe it is a habit that people has to overcome.
Some have developed habits (for example: deeply nested loops, unnecessarily large functions) that they perceive would be hard to support in a whitespace sensitive language. Some have developed an aesthetic dislike for hanging indents.
Because they are used to languages like C and JavaScript where they can align items as they please.
When it comes to Python, you have to indent code based on its context:
def Print():
ManyArgumentFunction(LongParam1,LongParam2,LongParam3,LongParam4...
In C, you could do:
void Print()
{
ManyArgumentFunction(LongParam1,
LongParam2,
LongParam3,...
}
The only complaints I (also of C++ background) have heard about Python are from people who don't like using the "Replace Tabs with Space" option in their IDE.
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