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

[Diez B. Roggisch]

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 exp for vars in iterable are called generator
expressions, and yield a generator.

Thus your code works.

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

[Macygasp]

On Aug 29, 3:51 pm, Diez B. Roggisch [EMAIL PROTECTED] wrote:
 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 exp for vars in iterable are called generator
 expressions, and yield a generator.

 Thus your code works.



Thanks, that's what I wanted to know.



 Diez

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