python - opening several txt files using while loop -

i have txt files names have following pattern:

arc.1.txt, arc.2.txt,...,arc.100.txt,..., arc.500.txt,...,arc.838.txt 

i know can write program using for loop open files 1 one, if total numbers of files. want know possible use while loop without counting number files open them ?

it possible use while loop assuming files numbered in sequential order:

i = 0 while true:     += 1     filename = 'arc.%d.txt' %     try:         open(filename, 'r') file_handle:             ...     except ioerror:         break 

though becomes pretty ugly nesting. you're better off getting list of filenames using glob.glob.

from glob import glob filenames = glob('arc.*.txt') filename in filenames:     open(filename) file_handle:         ... 

there race conditions associated second approach -- if file somehow gets deleted between when glob found , when time process file program have bad day.