Beginner's question about string's join() method

[Macygasp]

Hi,

Can anybody tell me why and how this is working:

>>','.join(str( a) for a in range(0,10))

'0,1,2,3,4,5,6, 7,8,9'

I find this a little weird because join takes a sequence as argument;
so, it means that somehow, from the "str(a) ... " expression, a
sequence can be generated.

If I write this:

>>(str(a) for a in range(0,10))

<generator object at 0x7f62d2e4d758>
it seems i'm getting a generator.

Can anybody explain this to me, please?

Thanks in advance.

[Diez B. Roggisch]

Re: Beginner's question about string's join() method

Macygasp wrote:

Hi,
>
Can anybody tell me why and how this is working:
>

>>>','.join(str (a) for a in range(0,10))

'0,1,2,3,4,5,6, 7,8,9'
>
I find this a little weird because join takes a sequence as argument;
so, it means that somehow, from the "str(a) ... " expression, a
sequence can be generated.
>
If I write this:

>>>(str(a) for a in range(0,10))

<generator object at 0x7f62d2e4d758>
it seems i'm getting a generator.
>
Can anybody explain this to me, please?

string.join takes an iterable. A generator is an iterable. Expressions of
the form "<expfor <varsin <iterable>" are called "generator
expressions", and yield a generator.

Thus your code works.

Diez

[Macygasp]

Re: Beginner's question about string's join() method

On Aug 29, 3:51 pm, "Diez B. Roggisch" <de...@nospam.w eb.dewrote:

Macygasp wrote:

Hi,

>

Can anybody tell me why and how this is working:

>

>>','.join(str( a) for a in range(0,10))

'0,1,2,3,4,5,6, 7,8,9'

>

I find this a little weird because join takes a sequence as argument;
so, it means that somehow, from the "str(a) ... " expression, a
sequence can be generated.

>

If I write this:

>>(str(a) for a in range(0,10))

<generator object at 0x7f62d2e4d758>
it seems i'm getting a generator.

>

Can anybody explain this to me, please?

>
string.join takes an iterable. A generator is an iterable. Expressions of
the form "<expfor <varsin <iterable>" are called "generator
expressions", and yield a generator.
>
Thus your code works.

Thanks, that's what I wanted to know.

>
Diez