Remove leading blank space from specific lines in .txt files

Hi. I need help removing the blank spaces in front of some of the lines in text files.

I want to remove the indent in front of the numbers, but want to leave the indent in front of the words. The begining numbers are the same(i.e., 2500.0, 5000.0, 10000.0, 20000.0, 50000.0), but the numbers following are different. In other words, every line is unique, making it difficult to use something like regexp() to find and replace for large data sets.

For example I have:

Name,proj1;
Edition,52;
Start;
Variable,1;
    DataReg,1,0.00,0.00,0.00;
    DataAng,1,00.0,00.0;
    Area,520.00;
    2500.0,180.047,180.997,190.946;
    5000.0,80.124,80.552,80.979;
    10000.0,40.039,40.252,40.465;
    20000.0,20.090,20.200,20.310;
    DataAng,2,00.0,00.0;
    Area,690.00;
    2500.0,130.687,140.407,150.128;
    5000.0,70.008,70.377,70.746;
    10000.0,30.675,30.868,40.062;
    20000.0,10.906,20.006,20.107;
    Area,710.00;
    2500.0 .......

Also, down the road I may want to remove space in front of selected words too (i.e., Area)

Answer 1

[Mathieu NOE]

hello

my suggestion below , tested on following text (I added a last section for my testing purposes)

Start;

Variable,1;

DataReg,1,0.00,0.00,0.00;

DataAng,1,00.0,00.0;

Area,520.00;

2500.0,180.047,180.997,190.946;

5000.0,80.124,80.552,80.979;

10000.0,40.039,40.252,40.465;

20000.0,20.090,20.200,20.310;

DataAng,2,00.0,00.0;

Area,690.00;

2500.0,130.687,140.407,150.128;

5000.0,70.008,70.377,70.746;

10000.0,30.675,30.868,40.062;

20000.0,10.906,20.006,20.107;

Area,710.00;

2500.0,130.687,140.407,150.128;

5000.0,70.008,70.377,70.746;

10000.0,30.675,30.868,40.062;

20000.0,10.906,20.006,20.107;

Location,710.00;

2500.0,130.687,140.407,150.128;

5000.0,70.008,70.377,70.746;

10000.0,30.675,30.868,40.062;

20000.0,10.906,20.006,20.107;

Filename = 'Document1.txt';
fid = fopen(Filename);
tline = fgetl(fid);

selected_words = {'Area'}; % test 1
% selected_words = {'Area','Location'}; % test 2

k = 0;
while ischar(tline)
    % check if first string is numeric and deblank 
    out = split(tline,',');
    k = k + 1;
    new_line{k} = tline;
    if ~isempty(str2num(out{1}))
        new_line{k} = strip(tline,'left'); % remove blanks left side (leading)
    else
        for ci = 1:numel(selected_words)
            if contains(tline,selected_words(ci))   
                new_line{k} = strip(tline,'left'); % remove blanks left side (leading) 
            end
        end 
    end
tline = fgetl(fid);
end

fclose(fid);
writecell(new_line', 'out.txt',"QuoteStrings",0);

[Timbo]

Worked like a charm! Thank you!

[Mathieu NOE]

Glad it helped !