iteration doesn't seem to work ??

[stef]

hello,

can someone tell me why the following iteration doesn't work,
and
how I should replace empty strings in a list with a default value.

>>v

['123', '345', '', '0.3']

>>for items in v:

.... if items=='':
.... items='3'
....

>>>
v

['123', '345', '', '0.3']

>>>

thanks,
Stef Mientki

[half.italian]

On May 16, 1:41 am, stef <[e-mail]:

hello,

can someone tell me why the following iteration doesn't work,
and
how I should replace empty strings in a list with a default value.

>>v

['123', '345', '', '0.3']

>>for items in v:

... if items=='':
... items='3'
...

>>>
>>v

['123', '345', '', '0.3']

>>>

thanks,
Stef Mientki

Inside the loop, 'items' is no longer referencing the list...its a
string.

>>v = ['123', '4', '567', '']
for i in v:

.... print type(i)
....
<type 'str'>...

This works

>>for j,i in enumerate(v):

.... if i=='':
.... v[j] = '3'
....

>>v

['123', '4', '567', '3']

>>>

~Sean

[stef]

hello Sean,

thanks very much for the explanation and solution.

cheers,
Stef Mientki

ha**********@gmail.com wrote:

On May 16, 1:41 am, stef <[e-mail]:

>hello,

can someone tell me why the following iteration doesn't work,
and
how I should replace empty strings in a list with a default value.

> >>v

['123', '345', '', '0.3']

> >>for items in v:

... if items=='':
... items='3'
...

> >>>
v

['123', '345', '', '0.3']

> >>>

thanks,
Stef Mientki

Inside the loop, 'items' is no longer referencing the list...its a
string.

>>>v = ['123', '4', '567', '']
for i in v:

... print type(i)
...
<type 'str'>...

This works

>>>for j,i in enumerate(v):

... if i=='':
... v[j] = '3'
...

>>>v

['123', '4', '567', '3']
~Sean

[Ant]

On May 16, 9:41 am, stef <[e-mail]:

hello,

can someone tell me why the following iteration doesn't work,
and
how I should replace empty strings in a list with a default value.

See the other reponse for the why. Here's another how, using list
comprehension.:

1 v = ['123', '345', '', '0.3']
2 v = [x if x else '3' for x in v]
3 v
3 = ['123', '345', '3', '0.3']

Note that this replaces the list, so won't be appropriate for
modifying a list passed in from elsewhere.

--
Ant...

http://antroy.blogspot.com/