Py3K idea: why not drop the colon?
mike at hobbshouse.org
Fri Nov 10 17:37:08 CET 2006
Ben Finney wrote:
> Please don't hide your new thread as a reply to an existing, unrelated
> message. Start a new message if your message isn't actually a reply.
My apologies. My email client was apparently hiding some important
headers from me.
>> The colon that divides the statement therefore seems redundant. The
>> colon could continue to be used for single-line statements:
>> if self.hungry: self.eat()
> Why have two different syntaxes for the same statement?
Why am I allowed separate statements with semi-colons in addition to
newlines? Why have triple-quoted long strings in addition to
single-quoted short strings? Why do I have to type backslash to continue
a line, except when I'm currently inside parens, brackets, or braces?
The answer is that it's a matter of convenience for the most common
case, with some exceptions allowed for the exceptional cases.
>> I think the colon could be omitted from every type of compound
>> statement: 'if', 'for', 'def', 'class', whatever. Am I missing
> A use case. What problem is being solved by introducing this
The same problem that is solved by not having to type parens around the
'if' conditional, a la C and its derivatives. That is, it's unnecessary
typing to no good advantage, IMHO. I was coding in Ruby for several
months and got very comfortable with just typing the if conditional and
hitting return, without any extra syntax. When I came back to Python, I
found that I felt annoyed every time I typed the colon, since it
obviously isn't required. The FAQ says that the colon increases
readability, but I'm skeptical. The indentation seems to provide more
than enough of a visual clue as to where the if conditional ends.
As far as using the FAQ as gospel, the FAQ also provides arguments for
why there isn't a with statement or a switch statement. The with
statement has already been implemented in 2.5 and there's a PEP to
implement switch (3103).
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