scope of optional arguments

[cseja]

If I call

print walk([1,2,3], [])
print walk([5,6,7])

I get

[1, 2, 3]
[4, 5, 6]

but when I call

print walk([1,2,3])
print walk([5,6,7])

I get

[1, 2, 3]
[1, 2, 3, 4, 5, 6]

at stdout, where

def walk(seq, result = []):
for item in seq:
result.append(item)
return result

Does that mean that the scope of optional arguments is global if they aren't
used and local if they are (or am I missing something here)?

Regards,
CS

 

[Steven Clark]

http://www.ferg.org/projects/python_gotchas.html#contents_item_6

 

[cseja]

Whoops, I meant to call

print walk([1,2,3], [])
print walk([4,5,6])

and

print walk([1,2,3])
print walk([4,5,6])

with

def walk(seq, result = []):
for item in seq:
result.append(item)
return result

The question is still the same: Why do both calls give different results?

Thank you very much for reading, I'm sorry for the inconvenience.

 

[cseja]

Thank you very much for your fast and usefull response, Steven. Have a nice
day.