File writing in Django keeps having IOError - django

Question

I'm running my app locally and I'm currently having an IOError during my file creation from the database. I am using Django 1.10, MongoDB as my database, and Celery 4.0.2 for my background tasks. The problem occurs in the tasks.py since that is where I access the db then store it in my django subfolder 'analysis_samples'.
Here is the traceback:
[2017-04-15 15:31:08,798: ERROR/PoolWorker-2] Task tasks.process_sample_input[0619194e-4300-4a1d-91b0-20766e048c4a] raised unexpected: IOError(2, 'No such file or directory')
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/celery/app/trace.py", line 367, in trace_task
R = retval = fun(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/celery/app/trace.py", line 622, in __protected_call__
return self.run(*args, **kwargs)
File "/home/user/django_apps/myapp/analysis/tasks.py", line 218, in process_sample_input
with open(sample_file_path, "w+") as f:
IOError: [Errno 2] No such file or directory: u'/home/user/django_apps/myapp/myapp/analysis_samples/58f1cc3c45015d127c3d68c1'
And here is the snippet of tasks.py:
from django.core.files import File
sys.path.append(settings.ANALYSIS_SAMPLES)
import base64
import os, sys
#shared_task(name='tasks.process_sample_input')
def process_sample_input(instance_id):
instance = Sample.objects.get(pk=instance_id)
#many code here..
try:
conn=pymongo.MongoClient(settings.MONGO_HOST, settings.MONGO_PORT)
db = conn.thugfs #connect to GridFS db of thug
thugfs_db = GridFS(db)
except pymongo.errors.ConnectionFailure, e:
logger.error("Could not connect to ThugFS MongoDB: %s" % e)
sample_file_folder = settings.ANALYSIS_SAMPLES
for sample_fs_id in sample_fs_ids:
sample_file = thugfs_db.get(ObjectId(sample_fs_id)).read()
sample_file = base64.b64decode(sample_file) #decode file from database
sample_file_path = os.path.join(sample_file_folder, sample_fs_id)
with open(sample_file_path, "w+") as f:
fileOut = File(f)
fileOut.write(sample_file)
settings.py:
ANALYSIS_SAMPLES = os.path.join(BASE_DIR, 'myapp/analysis_samples')
Can anyone see the point that caused the error? Any help will be appreciated.