example line
0         1         2         3         4         5         6         7         8         9         0         1         2         3         4         5         6         7         8         9         0         1         2         3         
012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789
 11 1220.344590 0.728E-23 0.681E+01 2612.7991 0.0425-9.981E+00 8.210E-01 1.002E+01 8.185E-01 0.00109-2.109E-01 1.068E+00 2.119E-01 1.072E+000.231          0 1 0          0 0 0 11  6  5       12  7  6      5766643033 1 1 1 1    69.0   75.0
mol,iso,ν,       S,        A,           E",    γ(N2), c1,       n1,       c2,       n2,       δ(N2)   d1,       q1,       d2,       q2,      γ(self),     Vupper,        Vlower, Rotupper,     Rotlower,     Ier(6),  IRef(6),     g_up,  g_low

parameter                              units                      FORTRAN      C++/python
----------------------------------------------------------------------------------------------
molecule id (mol)                       NA                           I2         %d2

isotopologue id (iso)                   NA                           I1         %d2

line position  ν                        cm^-1                        F12.6      %f12.6

line intensity  S                       (cm^-1)/(molecule cm^-2)     E10.3						%10.3e

Einstein A                              s^-1                         E10.3      %10.3e

lower state energy (term value) E"      cm^-1                        F10.4      %10.4f

N2-broadened half-width γ(N2)           cm^-1 atm^-1                 F7.4       %7.4f

temperature dependence coefficients
for γ(N2):  c1, c2                      cm^-1 atm^-1                 ES10.3E2   %10.3e
for γ(N2):  n1, n2                      unitless                     ES10.3E2   %10.3e

N2-pressure induced line shift δ(N2)    cm^-1 atm^-1                 F8.5       %8.5f

temperature dependence coefficients
for δ(N2):  d1, d2                      cm^-1 atm^-1                 ES10.3E2   %10.3e
for δ(N2):  q1, q2                      unitless                     ES10.3E2   %10.3e

self-broadened half-width γ(self)       cm^-1 atm^-1                 F5.3						 %5.3f          

upper state
vibrational quantum numbers             NA                           A15        %15s

lower state
vibrational quantum numbers             NA                           A15        %15s

upper state rotational quantum 
numbers J', Ka', Kc'                    NA                           A15        %15s

lower state rotational quantum 
numbers J", Ka", Kc"                    NA                           A15        %15s

error codes for
 ν, S, γ(N2), γself, n(N2),δ(N2)        NA                           6I1        6%d1

reference codes for
ν; S; γ(N2), γself ; n(N2) ; δ(N2)      NA                           6I2        6%d2

The upper and lower state 
statistical weights                     unitless                     F7.1      %7.1f
----------------------------------------------------------------------------------------------



FORTRAN code to read the file
c**************************************************************************************************************
      program read_txt
      
      implicit double precision(a-h,o-z)
      parameter (eof = -1)
      logical read_more_data
      real*4 n1,n2
      character*15 Qvib_up,Qvib_lo,Qrot_up,Qrot_lo
      
      open(1,file='H2O-N2_2019.txt',status='old')
      
  900 FORMAT(I2,I1,F12.6,2ES10.3E2,F10.4,F7.4,4ES10.3E2,F8.5,4ES10.3E2,F5.3,4A15,6I1,6I2,1x,2F7.1)
      
      nr = 0
      read_more_data=.TRUE.

      dowhile(read_more_data)
      read(1,900) mol,iso,freq,S,A,E_lower,g_N2,c1,n1,c2,n2,shift,d1,q1,d2,q2,gself,
     +            Qvib_up,Qvib_lo,Qrot_up,Qrot_lo,Ie_F,Ie_S,Ie_gN2,Ie_gself,Ie_nN2,Ie_dN2,
     +            IRef_F,IRef_S,IRef_g_N2,IRef_gself,IRef_n,IRef_shift_N2,gj_up,gj_lo

        if(ios.eq.eof)then
          write(*,*) '  Data input finished'
          read_more_data=.FALSE.
        else 
          nr = nr + 1

!         do your thing here
 
        endif

      enddo
      end
c**************************************************************************************************************
      
      
      
python code to read the file
#-------------------------------------------------
import decimal
import numpy as np

infile = 'H2O-N2_2019.txt'
H2ON2 = open(infile)
nt = 0

for line in H2ON2:
    nt = nt + 1
    line = line.rstrip()
    mol = line[0:2]
    iso = line[2:3]
    freq = float(line[3:15])
    S = float(line[15:25])
    A = float(line[25:35])
    E_lower = float(line[35:45])
    g_N2 = float(line[45:52])
    c1 = float(line[52:62])
    n1 = float(line[62:72])
    c2 = float(line[72:82])
    n2 = float(line[82:92])
    shift = float(line[92:100])
    d1 = float(line[100:110])
    q1 = float(line[110:120])
    d2 = float(line[120:130])
    q2 = float(line[130:140])
    gself = float(line[140:145])
    V_upper = line[145:160]
    V_lower = line[160:175]
    Qrot_up = line[175:190]
    Qrot_lo = line[190:205]
    Ie_F = line[205:206]
    Ie_S = line[206:207]
    Ie_gN2 = line[207:208]
    Ie_gself = line[208:209]
    Ie_nN2 = line[209:210]
    Ie_dN2 = line[210:211]
    IRef_F = line[211:213]
    IRef_S = line[213:215]
    IRef_g_N2 = line[215:217]
    IRef_gself =line[217:219]
    IRef_n = line[219:221]
    IRef_shift_N2 = line[221:223]
    gj_up = float(line[224:231])
    gj_lo = float(line[231:238])
    
#   do your thing here
#-------------------------------------------------