[Tutor] Extarcting data tables from a text file

[Mark Lawrence]

On 22/11/2013 16:25, Ruben Guerrero wrote:
> Dear tutor,
>
> I am  a beginner in python and I need  your guidance to  write a python
> script  to extract many nxn data tables of variable nunber of rows from
> a text file as in the following example
>
> Condensed to atoms (all electrons):
>                1          2          3          4          5          6
>       1  Cl   0.000000   0.304108  -0.101110  -0.108502  -0.108502
> 0.024111
>       2  C    0.304108   0.000000   0.515965   0.332621   0.332621
>   -0.004054
>       3  C   -0.101110   0.515965   0.000000  -0.013334  -0.013334
> 0.352916
>       4  H   -0.108502   0.332621  -0.013334   0.000000  -0.133436
>   -0.028924
>       5  H   -0.108502   0.332621  -0.013334  -0.133436   0.000000
>   -0.028924
>       6  H    0.024111  -0.004054   0.352916  -0.028924  -0.028924
> 0.000000
>       7  H   -0.030910  -0.074027   0.364085  -0.053300   0.048704
>   -0.123402
>       8  H   -0.030910  -0.074027   0.364085   0.048704  -0.053300
>   -0.123402
>                7          8
>       1  Cl  -0.030910  -0.030910
>       2  C   -0.074027  -0.074027
>       3  C    0.364085   0.364085
>       4  H   -0.053300   0.048704
>       5  H    0.048704  -0.053300
>       6  H   -0.123402  -0.123402
>       7  H    0.000000  -0.118520
>       8  H   -0.118520   0.000000
> Mulliken atomic charges:
>
> to other text  file with the numerical information in the table
>   concatenated by columns. The phrases in red always delimite the tables
> in the original file. In the python generated file I need the following:
>    a text flag (maybe  a line with the "O" charanter) delimiting each
> table, a second line with the total number of rows (atoms) in the table
> followed by a line with the ordered string of chemical symbols separated
> by a silgle space.
>
> My aim is load the numerical data from this file  to a c++ program to
> process this information.
>
> Thanks in advance.
>
> -Ruben.
>

I'm sorry but we don't write code for you here.  I suggest that you 
start out by reading the tutorial here 
http://docs.python.org/3/tutorial/index.html, try writing something and 
when and if you run into problems please feel free to get back to us.

-- 
Python is the second best programming language in the world.
But the best has yet to be invented.  Christian Tismer

Mark Lawrence