how do i change from string to list

[john]

I have the following

s = "spot"

which I would like to change to a list

l = ['s','p','o','t']

I have tried l = eval(s) but I get the error

File "<string>", line 1, in ?
NameError: spot

thank you all for your time

[Ivo Woltring]

str='spot'

lst = [] # declare the list first
for letter in str:
lst.append(letter) # append to the list

print lst

result: ['s', 'p', 'o', 't']

cheerz,
Ivo.
"john" <mi******@hotmail.com> wrote in message
news:99**************************@posting.google.c om...

I have the following

s = "spot"

which I would like to change to a list

l = ['s','p','o','t']

I have tried l = eval(s) but I get the error

File "<string>", line 1, in ?
NameError: spot

thank you all for your time

[Jorgen Grahn]

On 24 Oct 2004 11:05:28 -0700, john <mi******@hotmail.com> wrote:

I have the following

s = "spot"

which I would like to change to a list

list('spot')

['s', 'p', 'o', 't']

/Jorgen

--
// Jorgen Grahn <jgrahn@ Ph'nglui mglw'nafh Cthulhu
\X/ algonet.se> R'lyeh wgah'nagl fhtagn!

[Michael Hoffman]

Ivo Woltring wrote:

str='spot'

lst = [] # declare the list first
for letter in str:
lst.append(letter) # append to the list

print lst
I just would have used list("spot").
result: ['s', 'p', 'o', 't']

Same result but faster, more transparent, and with a lot less code.

Also, please don't top-post.
--
Michael Hoffman

[dataangel]

Michael Hoffman wrote:

Ivo Woltring wrote:

str='spot'

lst = [] # declare the list first
for letter in str:
lst.append(letter) # append to the list

print lst

I just would have used list("spot").

result: ['s', 'p', 'o', 't']

Same result but faster, more transparent, and with a lot less code.

Also, please don't top-post.

Also, if for some reason you didn't want to use list that would look
more elegant as a list comprehension:

y = "Hello!"
[x for x in y] ['H', 'e', 'l', 'l', 'o', '!']

[Ivo Woltring]

I agree completely!
Didn't know the list() though.
But all work so my answer is just as valid as yours

;-))
Ivo

"Ivo Woltring" <Th********@ivonet.nl> wrote in message
news:41*********************@reader20.nntp.hccnet. nl...

str='spot'

lst = [] # declare the list first
for letter in str:
lst.append(letter) # append to the list

print lst

result: ['s', 'p', 'o', 't']

cheerz,
Ivo.
"john" <mi******@hotmail.com> wrote in message
news:99**************************@posting.google.c om...

I have the following

s = "spot"

which I would like to change to a list

l = ['s','p','o','t']

I have tried l = eval(s) but I get the error

File "<string>", line 1, in ?
NameError: spot

thank you all for your time

[John Machin]

"Ivo Woltring" <Th********@ivonet.nl> wrote in message news:<41*********************@reader1.nntp.hccnet. nl>...

I agree completely!
Didn't know the list() though.
But all work so my answer is just as valid as yours

;-))
Ivo

This will probably work, too -- is it "valid"?

s = 'spot'
slen = len(s)
alist = [''] * slen
for i in range(slen):
alist[i] = s[i]

You can write code in Perl or Intercal [bonus points if you can tell
the difference] and it's "valid" in the sense that it works, but there
are many more considerations than that.

[BJörn Lindqvist]

How do you do the opposite? List to string? Shortest method I've found is:

''.join(["H", "e", "l", "l", "o"])

--
mvh Björn

[Michael Hoffman]

BJörn Lindqvist wrote:

How do you do the opposite? List to string? Shortest method I've found is:

''.join(["H", "e", "l", "l", "o"])

That is the obvious way to do it.
--
Michael Hoffman

[Peter Otten]

Michael Hoffman wrote:

BJörn Lindqvist wrote:

How do you do the opposite? List to string? Shortest method I've found
is:

>''.join(["H", "e", "l", "l", "o"])
That is the obvious way to do it.

We have different notions of obviousness, obviously:

str(['H', 'e', 'l', 'l', 'o'])

"['H', 'e', 'l', 'l', 'o']"

:-)

Peter

[Steve]

Hi John,
Although you already have the reply to your question, I thought I
should point one thing out. I have seen plenty of newbies wanting to
convert a string to a list so that they can do some sort of list
related manipulation on it. The good thing about python strings though
is, they are valid "sequences", which means that any sequence related
operations can also be carried out on strings.

For example:

s = "foobar"
for i in s: .... print i,
....
f o o b a r s[3:] 'bar' s[:-1] 'fooba'

....but I guess you already knew that :)

HTH someone,
Regards
Steve

[Andrew Dalke]

Michael Hoffman wrote:

> ''.join(["H", "e", "l", "l", "o"])

That is the obvious way to do it.

As compared to the less obvious ways of

import array
array.array("c", list("this is a test")).tostring() 'this is a test' import cStringIO
f = cStringIO.StringIO()
for c in list("this is a test"): .... f.write(c)
.... print f.getvalue() this is a test import operator
reduce(operator.add, list("this is a test")) 'this is a test' def join(fields): .... N = len(fields)
.... if N == 1: return fields[0]
.... if N == 2: return fields[0] + fields[1]
.... N = N//2
.... return join([join(fields[:N]), join(fields[N:])])
.... join(list("this is a test")) 'this is a test'

# only works for single character elements in the list
# (or larger strings that don't have ", ") s = "\"Let's go to the zoo!\", said \\Alice/\n"
print s "Let's go to the zoo!", said \Alice/
list(s) ['"', 'L', 'e', 't', "'", 's', ' ', 'g', 'o', ' ', 't', 'o', ' ', 't',
'h', 'e', ' ', 'z', 'o', 'o', '!', '"', ',', ' ', 's', 'a', 'i', 'd', '
', '\\', 'A', 'l', 'i', 'c', 'e', '/', '\n'] print eval(repr(list(s))[1:-1].replace(", ", " ")) "Let's go to the zoo!", said \Alice/

:)

Andrew
da***@dalkescientific.com

[Michael Hoffman]

Peter Otten wrote:

We have different notions of obviousness, obviously:

str(['H', 'e', 'l', 'l', 'o'])

"['H', 'e', 'l', 'l', 'o']"

:-)

That's a joke, right? :-)
--
Michael Hoffman

[Alex Martelli]

Andrew Dalke <ad****@mindspring.com> wrote:
...

>>> import cStringIO
>>> f = cStringIO.StringIO()
>>> for c in list("this is a test"):

... f.write(c)

f.writelines(list('this is a test'))

would appear to me a more natural approach than the loop. Yeah, the
method's name sucks -- it doesn't just write *lines*, etc. I guess it
originally came from some sort of parallel with 'readlines'.
Alex

[Ivo Woltring]

agreed
But I wasn't aware of the list() function and than my version wasn't so bad

but I agree about the more considerations though

Ivo

"John Machin" <sj******@lexicon.net> wrote in message
news:c7**************************@posting.google.c om...

"Ivo Woltring" <Th********@ivonet.nl> wrote in message

news:<41*********************@reader1.nntp.hccnet. nl>...

I agree completely!
Didn't know the list() though.
But all work so my answer is just as valid as yours

;-))
Ivo

This will probably work, too -- is it "valid"?

s = 'spot'
slen = len(s)
alist = [''] * slen
for i in range(slen):
alist[i] = s[i]

You can write code in Perl or Intercal [bonus points if you can tell
the difference] and it's "valid" in the sense that it works, but there
are many more considerations than that.