[Tutor] Output of list

2007-12-22 Thread Emil

hey

I want to be capable of converting a string into a list where all the items, in 
 the list, have a fixed length not equal to 1 e.g i have k = 'abcdefgh' and I 
want the fixed length for all the the items to be 2 then the list would look 
like ['ab', 'cd', 'ef, 'gh']. How do i do this?


- Emil   
_
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Re: [Tutor] Output of list

2007-12-22 Thread Ricardo Aráoz
Emil wrote:
 hey
 
 I want to be capable of converting a string into a list where all the items, 
 in  the list, have a fixed length not equal to 1 e.g i have k = 'abcdefgh' 
 and I want the fixed length for all the the items to be 2 then the list would 
 look like ['ab', 'cd', 'ef, 'gh']. How do i do this?
 
 

map(''.join, zip(k[::2], k[1::2]))
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Re: [Tutor] Output of list

2007-12-22 Thread Ricardo Aráoz
Emil wrote:
 hey
 
 I want to be capable of converting a string into a list where all the items, 
 in  the list, have a fixed length not equal to 1 e.g i have k = 'abcdefgh' 
 and I want the fixed length for all the the items to be 2 then the list would 
 look like ['ab', 'cd', 'ef, 'gh']. How do i do this?
 
 

Also : [''.join(i) for i in zip(k[::2], k[1::2])]
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Re: [Tutor] Output of list

2007-12-22 Thread Martin Walsh
Ricardo Aráoz wrote:
 Emil wrote:
 hey

 I want to be capable of converting a string into a list where all the items, 
 in  the list, have a fixed length not equal to 1 e.g i have k = 'abcdefgh' 
 and I want the fixed length for all the the items to be 2 then the list 
 would look like ['ab', 'cd', 'ef, 'gh']. How do i do this?


 
 Also : [''.join(i) for i in zip(k[::2], k[1::2])]

Cool use of 'zip' and extended slicing!

Just thought I would add that 'zip' truncates after the shortest
sequence, which would cause data loss for strings of odd length -- of
course, the OP may not consider this a problem.

In [1]: k = 'abcdefghi' # - note the 'i'

In [2]: len(k)
Out[2]: 9

In [3]: [''.join(i) for i in zip(k[::2], k[1::2])]
Out[3]: ['ab', 'cd', 'ef', 'gh'] # - 'i' is gone


HTH,
Marty





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Re: [Tutor] Output of list

2007-12-22 Thread Alan Gauld

Emil [EMAIL PROTECTED] wrote

 I want to be capable of converting a string into a list where all 
 the items,
  in  the list, have a fixed length not equal to 1

You can use list slicing to do this.
Combine with the stepsize parameter of the range function

 k = 'abcdefgh' and I want the fixed length for all the the
 items to be 2 then the list would look like ['ab', 'cd', 'ef, 'gh'].

k = 'abcdefgh'
new = []
for n in range(0,len(k),2):  # 2=stepsize
 new.append(k[n:n+2])   # use slice
print new

As a list comprehension that would be:

new = [k[n:n+2] for n in range(0,len(k),2)]

And as a more general function:

def splitStringByN(s,n):
   return [s[m:m+n] for m in range(0,len(s),n)]

Should work,

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld


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Re: [Tutor] Output of list

2007-12-22 Thread Ricardo Aráoz
Martin Walsh wrote:
 Ricardo Aráoz wrote:
 Emil wrote:
 hey

 I want to be capable of converting a string into a list where all the 
 items, in  the list, have a fixed length not equal to 1 e.g i have k = 
 'abcdefgh' and I want the fixed length for all the the items to be 2 then 
 the list would look like ['ab', 'cd', 'ef, 'gh']. How do i do this?


 Also : [''.join(i) for i in zip(k[::2], k[1::2])]
 
 Cool use of 'zip' and extended slicing!
 

Thx

 Just thought I would add that 'zip' truncates after the shortest
 sequence, which would cause data loss for strings of odd length -- of
 course, the OP may not consider this a problem.
 
 In [1]: k = 'abcdefghi' # - note the 'i'
 
 In [2]: len(k)
 Out[2]: 9
 
 In [3]: [''.join(i) for i in zip(k[::2], k[1::2])]
 Out[3]: ['ab', 'cd', 'ef', 'gh'] # - 'i' is gone
 

Could only think of :
[''.join(i) for i in zip(k[::2], k[1::2])] + list(k)[-(len(k)%2):0:-len(k)]

But maybe it is too complicated. There should be a simpler way.


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