Python File Remains Empty After Writing to it Issue -

i trying read url directly mysqldb table , tldextract domain url , find spf(sender policy framework) record domain.

when i'm trying write spf records of each , every domain scan,my ouput_spf_records.txt not contain records write.

not sure issue,any suggestions please ?

import sys import socket import dns.resolver import re import mysqldb import tldextract django.utils.encoding import smart_str, smart_unicode  def getspf (domain):    answers = dns.resolver.query(domain, 'txt')    rdata in answers:         txt_string in rdata.strings:                 if txt_string.startswith('v=spf1'):                         return txt_string.replace('v=spf1','')  db=mysqldb.connect("x.x.x.x","username","password","db_table") cursor=db.cursor() cursor.execute("select application_id,url app_info.app_urls") data=cursor.fetchall() x=0 while x<len(data):         c=tldextract.extract(data[x][1])         #print c         app_id=data[x][0]         #print app_id         d=str(app_id)+','+c[1]+'.'+c[2]         #with open('spfout.csv','a') out:         domain=smart_str(d)         #print domain         open('ouput_spf_records.txt','w') g:                 full_spf=""                 spf_rec=""                 y=domain.split(',')                 #print "y===",y,y[0],y[1]                 app_id=y[0]                 domains=y[1]                 try:                            full_spf=getspf(domains.strip())+"\n"                         spf_rec=app_id+","+full_spf                         print spf_rec                 except exception:                      pass                 g.write(spf_rec)         x=x+1         g.close() 

try openning file append mode, instead of w mode. w mode overwrites file in each iteration. example -

with open('ouput_spf_records.txt','a') g: 

most probably, last time open file in write mode, not write in since, catching , ignoring exceptions , causes empty file.

also, if know error expecting, should use except <error>: instead of except exception: . example -

try:        full_spf=getspf(domains.strip())+"\n"     spf_rec=app_id+","+full_spf     print spf_rec except <error want catch>:     pass