How to store incoming files with new names in Python? -

i have python3 based implementation incoming data checked , end result stored in file fixed name.

with open(filename.tar, 'wb') f:     f.write(dumpincomingdata) 

the filename.tar hard-coded of e.g. incomingfile.tar. problem file keeps getting over-written everytime new incoming data detected , not want. want files written everytime written in different file everytime viz. :

• incomingdata1.tar

• incomingdata2.tar ...

how can execute idea in pythonic way?

code snippet

 os import chdir  path = '/tmp/'  filename = 'incomingdata.tar'    while true:        processes         if(condition = true):             print("file decoded")             chdir(path)             open(filename, 'wb') f:                  f.write(dumpdata)             break 

dumpdata function of module using , shouldn't of concern here.

why not count sequence number until hit free filename?

from itertools import count import os  def open_next_file(template='incomingdata{serial}.tar'):     filename in (template.format(serial=serial) serial in count()):         try:             return open(filename, 'xb')         except oserror:             if not os.path.exists(filename):                 raise 

this yield open file filename next available sequence incomingdata0.tar, incomingdata1.tar, , on. operation atomic long os.open(..., o_creat | o_excl) atomic (which is).

for python 2 not support open mode 'x', possible emulate behavior using os.open(..., os.o_creat | os.o_excl). in python 3 mode='xb' sufficient.