Andrew Savige wrote:
I'd like to convert the following Perl code to Python:
use strict;
{
my %private_hash = ( A=>42, B=>69 );
sub public_fn {
my $param = shift;
return $private_hash{$param};
}
}
print public_fn("A"); # good: prints 42
my $x = $private_hash{"A"}; # error: good, hash not in scope
The real code is more complex; the above is a simplified example.
Notice that this code uses Perl's lexical scope to hide the
%private_hash variable, but not the public_fn() function.
While I could convert this code to the following Python code:
private_hash = dict( A=42, B=69 )
def public_fn(param):
return private_hash[param]
print public_fn("A") # good: prints 42
x = private_hash["A"] # works: oops, hash is in scope
Why would you do that if you do not want to do that?
I'm not happy with that because I'd like to limit the scope of the
private_hash variable so that it is known only inside public_fn.
def public_fn():
private_hash = dict( A=42, B=69 )
def public_fn(param):
return private_hash[param]
return public_fn
public_fn = public_fn()
print (public_fn("A"))
x = private_hash["A"]
# outputs
42
Traceback (most recent call last):
File "C:\Programs\Python31\misc\t1", line 8, in <module>
x = private_hash["A"]
NameError: name 'private_hash' is not defined
Terry Jan Reedy
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