error in accessing table created in django in the python code
The exception says: no such table: search_keywords, which is quite self-explanatory and means that there is no database table with such name. So:

You may be using relative path to db file in settings.py, which resolves to a different db depending on place where you execute the script. Try to use absolute path and see if it helps.
You have not synced your models with the database. Run manage.py syncdb to generate the database tables.
Now on writing path as sys.path.insert(0,'/home/pooja/Desktop/mysite'), it ran fine asked me for the word tobe searched and gave this error: 

Traceback (most recent call last):
File "call.py", line 32, in 
s.save()
File
  "/usr/local/lib/python2.6/dist-packages/django/db/models/base.py",
  line 463, in save
self.save_base(using=using, force_insert=force_insert,
  force_update=force_update)
File
  "/usr/local/lib/python2.6/dist-packages/django/db/models/base.py",
  line 524, in 
save_base
manager.using(using).filter(pk=pk_val).exists())):
File
  "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py",
  line 562, in exists
return self.query.has_results(using=self.db)
File
  "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/query.py",
  line 441, in has_results
return bool(compiler.execute_sql(SINGLE))
File
  "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/compiler.py",
  line 818, in execute_sql
cursor.execute(sql, params)
File
  "/usr/local/lib/python2.6/dist-packages/django/db/backends/util.py",
  line 40, in execute
return self.cursor.execute(sql, params)    File
  "/usr/local/lib/python2.6/dist-packages/django/db/backends/sqlite3/base.py",
  line 337, in execute
       return Database.Cursor.execute(self, query, params)
django.db.utils.DatabaseError: no such table: search_keywords

Please help!!