Hi all,
I can use list comprehension to create list quickly. So I expected that I
can created tuple quickly with the same syntax. But I found that the
same syntax will get a generator, not a tuple. Here is my example:
In [147]: a = (i for i in range(10))
In [148]: b = [i for i in range(10)]
In [149]: type(a)
Out[149]: <type 'generator'>
In [150]: type(b)
Out[150]: <type 'list'>
Is there a way to create a tuple like (1, 2, 3, 4, 5, 6, 7, 8, 9)
quickly? I already I can use tuple() on a list which is created by list
comprehension to get a desired tuple.
Regards,
Xiao Jianfeng
6  2006 
On 13 Cze, 09:45, "fdu.xia...@gma il.com" <fdu.xia...@gma il.comwrote:
Hi all,
I can use list comprehension to create list quickly. So I expected that I
can created tuple quickly with the same syntax. But I found that the
same syntax will get a generator, not a tuple. Here is my example:
In [147]: a = (i for i in range(10))
In [148]: b = [i for i in range(10)]
In [149]: type(a)
Out[149]: <type 'generator'>
In [150]: type(b)
Out[150]: <type 'list'>
Is there a way to create a tuple like (1, 2, 3, 4, 5, 6, 7, 8, 9)
quickly? I already I can use tuple() on a list which is created by list
comprehension to get a desired tuple.
Regards,
Xiao Jianfeng
You should do it like this:
>>a = tuple([i for i in range(10)])
type(a)
<type 'tuple'>
>>print a[0]
0
>>print a[9]
9
>>print a
(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
Cheers,
Marek
markacy wrote:
On 13 Cze, 09:45, "fdu.xia...@gma il.com" <fdu.xia...@gma il.comwrote:
>Hi all,
I can use list comprehension to create list quickly. So I expected that I
can created tuple quickly with the same syntax. But I found that the
same syntax will get a generator, not a tuple. Here is my example:
In [147]: a = (i for i in range(10))
In [148]: b = [i for i in range(10)]
In [149]: type(a)
Out[149]: <type 'generator'>
In [150]: type(b)
Out[150]: <type 'list'>
Is there a way to create a tuple like (1, 2, 3, 4, 5, 6, 7, 8, 9)
quickly? I already I can use tuple() on a list which is created by list
comprehensio n to get a desired tuple.
Regards,
Xiao Jianfeng
You should do it like this:
>>>a = tuple([i for i in range(10)])
type(a)
<type 'tuple'>
>>>print a[0]
0
>>>print a[9]
9
>>>print a
(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
No need to create the intermediate list, a generator expression works just
fine:
a = tuple(i for i in range(10))
Diez
"fd********@gma il.com" <fd********@gma il.comwrites:
I can use list comprehension to create list quickly. So I expected
that I can created tuple quickly with the same syntax.
Nope. The list comprehension syntax creates lists.
But I found that the same syntax will get a generator, not a
tuple. Here is my example:
In [147]: a = (i for i in range(10))
This contains no commas, so I don't know why you think it has anything
to do with a tuple.
Bear in mind that parentheses have nothing to do with the syntax for
creating a tuple; the parentheses merely determine parsing order, and
can enclose any expression.
Is there a way to create a tuple like (1, 2, 3, 4, 5, 6, 7, 8, 9)
quickly?
tuple(range(1, 10))
--
\ "Know what I hate most? Rhetorical questions." -- Henry N. Camp |
`\ |
_o__) |
Ben Finney
In <5d************ *@mid.uni-berlin.de>, Diez B. Roggisch wrote:
No need to create the intermediate list, a generator expression works just
fine:
a = tuple(i for i in range(10))
But `range()` creates the intermediate list anyway. ;-)
a = tuple(xrange(10 ))
Ciao,
Marc 'BlackJack' Rintsch fd********@gmai l.com a écrit :
Hi all,
I can use list comprehension to create list quickly. So I expected that I
can created tuple quickly with the same syntax. But I found that the
same syntax will get a generator, not a tuple. Here is my example:
In [147]: a = (i for i in range(10))
In [148]: b = [i for i in range(10)]
In [149]: type(a)
Out[149]: <type 'generator'>
In [150]: type(b)
Out[150]: <type 'list'>
Is there a way to create a tuple like (1, 2, 3, 4, 5, 6, 7, 8, 9)
quickly?
t = tuple(range(1, 10))
If the use of 'range' in your above snippet was just for the exemple,
see Diez's answer.
On Jun 13, 5:37 am, Marc 'BlackJack' Rintsch <bj_...@gmx.net wrote:
In <5d9ngkF32j8i.. .@mid.uni-berlin.de>, Diez B. Roggisch wrote:
No need to create the intermediate list, a generator expression works just
fine:
a = tuple(i for i in range(10))
But `range()` creates the intermediate list anyway. ;-)
I imagine that's special case. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics | |
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-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
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