Paul Rubin wrote:
> John Nagle <[EMAIL PROTECTED]> writes:
>
>> In a language with few declarations, it's probably best not to
>>have too many different nested scopes. Python has a reasonable
>>compromise in this area. Functions and classes have a scope, but
>>"if" and "for" do not. That works adequately.
>
>
> I think Perl did this pretty good. If you say "my $i" that declares
> $i to have block scope, and it's considered good practice to do this,
> but it's not required. You can say "for (my $i=0; $i < 5; $i++) { ... }"
> and that gives $i the same scope as the for loop. Come to think of it
> you can do something similar in C++.
Those languages have local declarations. "my" is a local
declaration. If you have explicit declarations, explict block
scope is no problem. Without that, there are problems. Consider
def foo(s, sname) :
if s is None :
result = ""
else :
result = s
msg = "Value of %s is %s" % (sname, result)
return(msg)
It's not that unusual in Python to initialize a variable on
two converging paths. With block scope, you'd break
code that did that.
John Nagle
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