How to use the presto.infodata.infodata function in presto

short_nM = options.nM // 1000000

    # The basename of the data files
    if argv[1].endswith(".dat"):
        basename = "../"+argv[1][:-4]
    else:
        basename = "../"+argv[1]

    # Get the bird file (the first birdie file in the directory!)
    birdname = glob("../*.birds")
    if birdname:
        birdname = birdname[0]

    outnamebase = options.outdir+basename[3:]
    inf = read_inffile(basename)
    idata = infodata.infodata(basename+".inf")
    N = inf.N
    t0i = inf.mjd_i
    t0f = inf.mjd_f
    num = 0
    point = 0
    T = options.nM * inf.dt / 86400.0
    baryv = get_baryv(idata.RA, idata.DEC, idata.epoch, T, obs='GB')
    print("Baryv = ", baryv)
    inf.N = options.nM
    inf.numonoff = 0
    nM = options.nM // 1000000
    while point + options.nM < N:
        pM = point // 1000000
        outname = basename[3:]+'_%03dM'%nM+'_%02d'%num
        stdout.write('\n'+outname+'\n\n')
        inf.name = outname

#!/usr/bin/env python
from __future__ import (print_function,division)
import presto.psr_utils as pu
import sys
from presto.infodata import infodata

if len(sys.argv) != 2:
    print("chooseN ")
    print("    Prints a good value for fast FFTs to be used for -numout in prepdata/prepsubband")
    sys.exit(1)

if sys.argv[1].endswith('.inf'):
    inf = infodata(sys.argv[1])
    n = inf.N
else:
    try:
        n = int(sys.argv[1])
    except:
        print("chooseN ")
        print("    Prints a good value for fast FFTs to be used for -numout in prepdata/prepsubband")
        sys.exit(2)

print(pu.choose_N(n))

opts.is_no_detrend = True  # we don't do detrending for events
		if opts.mjd == '' and not opts.is_chandra:
			print("Error: for events' file start MJD _must_ be given with --mjd option or --chandra option!")
			sys.exit(1)
		if opts.nbins == -1:
			print("Error: number of bins _must_ be given with --nbins option!")
			sys.exit(1)
		if opts.rebin != 1:
			print("Event data can not be re-binned")
			opts.rebin = 1
	else:
		if (opts.mjd == '' and not opts.is_chandra) or opts.tsamp == '' or opts.psrname == '':
			# reading inf-file to get corresponding info
			inffile = datfile.split(".dat")[0] + ".inf"
			try:
				id = inf.infodata(inffile)
				tsamp = id.dt        # sampling time
				startmjd = id.epoch  # start MJD
                		source = id.object   # pulsar name
			except:
				print("Error: Can't read the inf-file '%s'!" % (inffile,))
				sys.exit(1)

	# overwriting MJD, tsamp, pulsarname from the command line if given
	if opts.is_chandra:
		opts.mjd = "50814.0"
		print("Chandra event file. Reference start MJD is %s" % (opts.mjd))
	if opts.mjd != '':
		startmjd = float(opts.mjd)
	if opts.tsamp != '':
		tsamp = float(opts.tsamp)
	if opts.psrname != '':

def get_obs_info(inffile):
    """Read in an .inf file to extract observation information.
        Return observation RA, Dec, duration, and source name.
    """
    inf = infodata.infodata(inffile)
    T = inf.dt * inf.N # total observation time (s)
    RA = inf.RA
    dec = inf.DEC
    src = inf.object
    MJD = inf.epoch
    telescope = inf.telescope
    freq = (inf.numchan/2-0.5)*inf.chan_width+inf.lofreq # center freq
    return {'T': T, 'RA': RA, 'dec': dec, 'src': src, 'MJD': MJD, 'telescope': telescope, 'freq': freq}

def get_obs_info(inffile):
    """Read in an .inf file to extract observation information.
        Return observation RA, Dec, duration, and source name.
    """
    inf = infodata.infodata(inffile)
    T = inf.dt * inf.N # total observation time (s)
    RA = inf.RA
    dec = inf.DEC
    src = inf.object
    MJD = inf.epoch
    telescope = inf.telescope
    freq = (inf.numchan/2-0.5)*inf.chan_width+inf.lofreq # center freq
    return {'T': T, 'RA': RA, 'dec': dec, 'src': src, 'MJD': MJD, 'telescope': telescope, 'freq': freq}

PLOTTYPE = rrattrap_config.PLOTTYPE
        RANKS_TO_WRITE = rrattrap_config.RANKS_TO_WRITE
        RANKS_TO_PLOT = rrattrap_config.RANKS_TO_PLOT
    else:
        CLOSE_DM = options.close_dm
        MIN_GROUP = options.min_group
        TIME_THRESH = options.time_thresh
        DM_THRESH = options.dm_thresh
        MIN_SIGMA = options.min_sigma
        PLOT = options.plot
        PLOTTYPE = options.plottype
        RANKS_TO_WRITE = list(RANKS[RANKS>options.min_ranktowrite]) 
        RANKS_TO_PLOT = list(RANKS[RANKS>options.min_ranktoplot])
    
    inffile = options.inffile
    inf = infodata.infodata(inffile)    
    print_debug("Beginning read_sp_files... "+strftime("%Y-%m-%d %H:%M:%S"))
    
    groups = spio.read_sp_files(args[1:])[0]
    print_debug("Finished read_sp_files, beginning create_groups... " +
                strftime("%Y-%m-%d %H:%M:%S"))
    print_debug("Number of single pulse events: %d " % len(groups))
    
    groups = create_groups(groups, inffile, min_nearby=1, ignore_obs_end=10, time_thresh=TIME_THRESH, dm_thresh=DM_THRESH, use_dmplan=options.use_DMplan) # ignore the last 10 seconds of the obs, for palfa
    print_debug("Number of groups: %d " % len(groups))
    print_debug("Finished create_groups, beginning grouping_sp_dmt... " +
                    strftime("%Y-%m-%d %H:%M:%S"))
    
    grouping_sp_dmt(groups, use_dmplan=options.use_DMplan, time_thresh=TIME_THRESH, dm_thresh=DM_THRESH)
    print_debug("Number of groups (after initial grouping): %d " % len(groups))
    print_debug("Finished grouping_sp_dmt, beginning flag_noise... " + 
                strftime("%Y-%m-%d %H:%M:%S"))