help: output arrays into file as column

[bei]

Hi,

I am trying to write several arrays into one file, with one arrays in
one column. Each array (column) is seperated by space.
ie. a=[1,2,3, 4] b=[5,6,7,8] c=[9,10,11,12]
1 5 9
2 6 10
3 7 11
4 8 12

Now I use the function file.writelines (a), file.writelines (b),
file.writelines (c). And the output is a sequence of strings without
newlines between a, b ,c . Also each array stays in row other than
column.

I am a new comer to python.Any idea about this is appreciated!

Bei

[Simon Forman]

Re: help: output arrays into file as column

bei wrote:

Hi,
>
I am trying to write several arrays into one file, with one arrays in
one column. Each array (column) is seperated by space.
ie. a=[1,2,3, 4] b=[5,6,7,8] c=[9,10,11,12]
1 5 9
2 6 10
3 7 11
4 8 12
>
Now I use the function file.writelines (a), file.writelines (b),
file.writelines (c). And the output is a sequence of strings without
newlines between a, b ,c . Also each array stays in row other than
column.
>
I am a new comer to python.Any idea about this is appreciated!
>
Bei

Hi Bei,

file.writelines () works with lists of strings, not lists of numbers, so
I'm going to assume that a, b, and c are already lists of strings..

You can use the zip() function to change the lists in the way you want
to:

|>a=['1','2','3','4']; b=['5','6','7','8']; c=['9','10','11',' 12']
|>zip(a, b, c)
[('1', '5', '9'), ('2', '6', '10'), ('3', '7', '11'), ('4', '8', '12')]

now that you have the data for each line, you can combine them with the
string join() method:

|>data = zip(a, b, c)
|>for datum in data:
.... print ' '.join(datum)
....
1 5 9
2 6 10
3 7 11
4 8 12

You can print to an open file object, so the above loop will do what
you need:

|>f = open('output.tx t', 'w')
|>for datum in data:
.... print >f, ' '.join(datum)
....
|>f.close()
|>print open('output.tx t').read()
1 5 9
2 6 10
3 7 11
4 8 12


I hope that helps!

Peace,
~Simon

[bei]

Re: help: output arrays into file as column

Hi,Simon,

Thanks for your reply.It's very helpful :)
But I am sorry for my given example.Actuall y, my data in the arrays are
all float point datas.And I use integer in the example.The code is like
this.
("x,v,...,h" are floating point number arrays)

pos=str(x)
vel=str(v)
ene=str(u)
den=str(rho)
pre=str(P)
hms=str(h)
datas=zip(pos,v el,ene,den,pre, hms)
filename="data. dat"
file=open(filen ame,"w")
for datum in datas:
print >>file, ' '.join(datum)
file.close()


However, the result seperate each point in floating number , but not
regard them as a whole. It's like this :


[ [ [ [ [ [
- 0 1 1 1 0
0 . . . . .
.. 0 4 0 0 0
5 , 9 , , 0
9 9 3
9 0 9 1 1 7
9 . 9 . . 6
9 0 9 0 0 8
9 , 9 , , 7
9 9 5
9 0 9 1 1 ,
9 . 9 . .
9 0 9 0 0 0
9 , 9 , , .
9 9 0
9 0 9 1 1 0
9 . 9 . . 3
9 0 8 0 0 7
9 , , , , 6
8 8
, 0 1 1 1 7
. . . . 5
- 0 4 0 0 ,
0 , 9 , ,
.. 9 0
5 0 9 1 1 .
9 . 9 . . 0
6 0 9 0 0 0
9 , 9 , , 3
9 9 7
2 0 9 1 1 6
4 . 9 . . 8
8 0 9 0 0 7
1 , 9 , , 5
2 9 ,
0 0 9 1 1
3 . 9 . . 0
0 0 8 0 0 .
0 , , , , 0
7 0
5 0 1 1 1 3
2 . . . . 7
, 0 4 0 0 6
, 9 , , 8
- 9 7
0 0 9 1 1 5
.. . 9 . . ,
5 0 9 0 0
9 , 9 , , 0
3 9 .
9 0 9 1 1 0
8 . 9 . . 0
4 0 9 0 0 3
9 , 9 , , 7
6 9 6
2 0 9 1 1 8
4 . 9 . . 7
0 0 8 0 0 5
6 , , , , ,
0
1 0 1 1 1 0
5 . . . . .
0 0 4 0 0 0
6 , 9 , , 0
, 9 3
0 9 1 1 7
- . 9 . . 6
0 0 9 0 0 8
.. , 9 , , 7
5 9 5
9 0 9 1 1 ,
0 . 9 . .
9 0 9 0 0 0
7 , 9 , , .
7 9 0
4 0 9 1 1 0
4 . 9 . . 3
3 0 8 0 0 7
6 , , , , 6
0 8
9 0 1 1 1 7
0 . . . . 5
2 0 4 0 0 ,
2 , 9 , ,
4 9 0
9 0 9 1 1 .
, . 9 . . 0
0 9 0 0 0
......

Do you have a way to work this out? Thank you very much, And sorry
again for my incorrect example.

Bei




Simon Forman wrote:

bei wrote:

Hi,

I am trying to write several arrays into one file, with one arrays in
one column. Each array (column) is seperated by space.
ie. a=[1,2,3, 4] b=[5,6,7,8] c=[9,10,11,12]
1 5 9
2 6 10
3 7 11
4 8 12

Now I use the function file.writelines (a), file.writelines (b),
file.writelines (c). And the output is a sequence of strings without
newlines between a, b ,c . Also each array stays in row other than
column.

I am a new comer to python.Any idea about this is appreciated!

Bei

>
Hi Bei,
>
file.writelines () works with lists of strings, not lists of numbers, so
I'm going to assume that a, b, and c are already lists of strings..
>
You can use the zip() function to change the lists in the way you want
to:
>
|>a=['1','2','3','4']; b=['5','6','7','8']; c=['9','10','11',' 12']
|>zip(a, b, c)
[('1', '5', '9'), ('2', '6', '10'), ('3', '7', '11'), ('4', '8', '12')]
>
now that you have the data for each line, you can combine them with the
string join() method:
>
|>data = zip(a, b, c)
|>for datum in data:
... print ' '.join(datum)
...
1 5 9
2 6 10
3 7 11
4 8 12
>
You can print to an open file object, so the above loop will do what
you need:
>
|>f = open('output.tx t', 'w')
|>for datum in data:
... print >f, ' '.join(datum)
...
|>f.close()
|>print open('output.tx t').read()
1 5 9
2 6 10
3 7 11
4 8 12
>
>
I hope that helps!
>
Peace,
~Simon

[Bruno Desthuilliers]

Re: help: output arrays into file as column

bei a écrit :
<otPlease don't top-post</ot>

Hi,Simon,
>
Thanks for your reply.It's very helpful :)
But I am sorry for my given example.Actuall y, my data in the arrays are
all float point datas.And I use integer in the example.The code is like
this.
("x,v,...,h" are floating point number arrays)

Arrays or lists ?

pos=str(x)

Why on earth are you doing this ?

vel=str(v)
ene=str(u)
den=str(rho)
pre=str(P)
hms=str(h)
datas=zip(pos,v el,ene,den,pre, hms)

datas = zip(v, u, rho, P, h)

filename="data. dat"
file=open(filen ame,"w")

This shadows the builtin 'file' type. Using another name may be a good idea.

for datum in datas:
print >>file, ' '.join(datum)

print >file, ' '.join(map(str, datum))

file.close()

>
However, the result seperate each point in floating number , but not
regard them as a whole. It's like this :
>
>
[ [ [ [ [ [
- 0 1 1 1 0
0 . . . . .
. 0 4 0 0 0
5 , 9 , , 0
9 9 3

(snip)

One of the nice things with Python is the interactive shell. Let's use it:
Python 2.4.1 (#1, Jul 23 2005, 00:37:37)
[GCC 3.3.4 20040623 (Gentoo Linux 3.3.4-r1, ssp-3.3.2-2, pie-8.7.6)] on
linux2
Type "help", "copyright" , "credits" or "license" for more information.

>>a = map(float, range(0,3))
>>a

[0.0, 1.0, 2.0]

>>b = map(float, range(12, 15))
>>c = map(float, range(7, 10))
>>a, b, c

([0.0, 1.0, 2.0], [12.0, 13.0, 14.0], [7.0, 8.0, 9.0])

>>str(a)

'[0.0, 1.0, 2.0]'

>>list(str(a) )

['[', '0', '.', '0', ',', ' ', '1', '.', '0', ',', ' ', '2', '.', '0', ']']

>>zip(str(a), str(b), str(c))

[('[', '[', '['), ('0', '1', '7'), ('.', '2', '.'), ('0', '.', '0'),
(',', '0', ','), (' ', ',', ' '), ('1', ' ', '8'), ('.', '1', '.'),
('0', '3', '0'), (',', '.', ','), (' ', '0', ' '), ('2', ',', '9'),
('.', ' ', '.'), ('0', '1', '0'), (']', '4', ']')]

>>zip(a, b, c)

[(0.0, 12.0, 7.0), (1.0, 13.0, 8.0), (2.0, 14.0, 9.0)]

>>>

HTH

[bei]

Re: help: output arrays into file as column

Perfect! It works. Thanks Bruno.
Bruno Desthuilliers wrote:

bei a écrit :
<otPlease don't top-post</ot>
>

Hi,Simon,

Thanks for your reply.It's very helpful :)
But I am sorry for my given example.Actuall y, my data in the arrays are
all float point datas.And I use integer in the example.The code is like
this.
("x,v,...,h" are floating point number arrays)

>
Arrays or lists ?
>

pos=str(x)

>
Why on earth are you doing this ?
>

vel=str(v)
ene=str(u)
den=str(rho)
pre=str(P)
hms=str(h)
datas=zip(pos,v el,ene,den,pre, hms)

>
datas = zip(v, u, rho, P, h)
>

filename="data. dat"
file=open(filen ame,"w")

>
This shadows the builtin 'file' type. Using another name may be a good idea.
>

for datum in datas:
print >>file, ' '.join(datum)

print >file, ' '.join(map(str, datum))
>

file.close()

>
>
>
>

However, the result seperate each point in floating number , but not
regard them as a whole. It's like this :


[ [ [ [ [ [
- 0 1 1 1 0
0 . . . . .
. 0 4 0 0 0
5 , 9 , , 0
9 9 3

>
(snip)
>
One of the nice things with Python is the interactive shell. Let's use it:
Python 2.4.1 (#1, Jul 23 2005, 00:37:37)
[GCC 3.3.4 20040623 (Gentoo Linux 3.3.4-r1, ssp-3.3.2-2, pie-8.7.6)] on
linux2
Type "help", "copyright" , "credits" or "license" for more information.

>>a = map(float, range(0,3))
>>a

[0.0, 1.0, 2.0]

>>b = map(float, range(12, 15))
>>c = map(float, range(7, 10))
>>a, b, c

([0.0, 1.0, 2.0], [12.0, 13.0, 14.0], [7.0, 8.0, 9.0])

>>str(a)

'[0.0, 1.0, 2.0]'

>>list(str(a) )

['[', '0', '.', '0', ',', ' ', '1', '.', '0', ',', ' ', '2', '.', '0', ']']

>>zip(str(a), str(b), str(c))

[('[', '[', '['), ('0', '1', '7'), ('.', '2', '.'), ('0', '.', '0'),
(',', '0', ','), (' ', ',', ' '), ('1', ' ', '8'), ('.', '1', '.'),
('0', '3', '0'), (',', '.', ','), (' ', '0', ' '), ('2', ',', '9'),
('.', ' ', '.'), ('0', '1', '0'), (']', '4', ']')]

>>zip(a, b, c)

[(0.0, 12.0, 7.0), (1.0, 13.0, 8.0), (2.0, 14.0, 9.0)]

>>>

HTH