python - Add header to np.matrix -

i trying export numpy matrix ascii format, want add header first.

my code concept this:

1. import ascii file np.ndarray, matrix
2. take header of (first 6 rows). header contains both float values , characters
3. take rows of not header (from rows 6 last row), giving array b
4. apply functions on b
5. save ascii in form: header(a) + b

i tried following:

try 1:

import numpy np = np.genfromtxt('......input\chm_plot_1.txt', dtype=none, delimiter='\t') header = a[0:6] b = a[6:] mat_out = np.concatenate([a,b]) np.savetxt('........out.txt', mat_out, delimiter='\t') 

,but gives error:

typeerror: mismatch between array dtype ('|s3973') , format specifier ('%.18e')

try 2:

import numpy np = np.genfromtxt('......input\chm_plot_1.txt', dtype=none, delimiter='\t') header = a[0:6] headers = np.vstack(header) head_list = headers.tolist() head_str = ''.join(str(v) v in head_list) b = a[6:] np.savetxt('\out.txt', b, header = head_str,  delimiter='\t') 

,which gives same error:

typeerror: mismatch between array dtype ('|s3973') , format specifier ('%.18e')

try 3:

import numpy np import linecache  = np.genfromtxt('.............\input\chm_plot_1.txt', dtype=none, delimiter='\t') line1 = linecache.getline('.............input\chm_plot_1.txt', 1) line2 = linecache.getline('.............input\chm_plot_1.txt', 2) line3 = linecache.getline('.............input\chm_plot_1.txt', 3) line4 = linecache.getline('.............input\chm_plot_1.txt', 4) line5 = linecache.getline('.............input\chm_plot_1.txt', 5) line6 = linecache.getline('.............input\chm_plot_1.txt', 6) header2 = line1 header2 += line2 header2 += line3 header2 += line4 header2 += line5 header2 += line6  b = a[6:] np.savetxt('........\out.txt', b , header = header2,  delimiter='\t') 

, gives me same error:

typeerror: mismatch between array dtype ('|s3973') , format specifier ('%.18e')

the array has first lines this:

print a[0:8] #starting row 6, rows have 100+ values, header first 6 rows

['ncols         371' 'nrows         435' 'xllcorner     520298.0053'  'yllcorner     436731.3065' 'cellsize      1' 'nodata_value  -9999' '16.52002 15.90161 15.96692 20.32922 20.59827 18.28137 18.83533 17.66 ....... '13.16687 17.09497 7.309204 20.83655 19.05078 17.68591 17.88464 ...... '] 

any appreciated! :)

edit: uploaded sample input data (chm_plot_1.txt). link below: http://we.tl/mjgbe4qirm

edit2: following answer, problem inserts "#" character @ beginning of header lines, in image below below. also, there 1 supplementary line, 7th one, should removed.

edit 3: think error

valueerror: invalid literal float()

is due different formats of data in sample vs full files. although both .txt, arranged differently, in picture below.

the problem header has not same format data.

a way solve : treat header normal file text, , data numeric.

with open('chm_plot_1_sample.txt') f :        header="".join([f.readline() in range(6)])[:-1] a=np.loadtxt('chm_plot_1_sample.txt',delimiter='\t',skiprows=6) a=a/2  # treatement np.savetxt('out.txt',a,delimiter='\t',header=header,comments='')