Which user opens a file in python? - python

I am working with django and celery. In my celery task, I instantiate a class and that class is responsible for generating and mailing a CSV file.
My problem is I am getting IOError: [Errno 13] Permission denied
when i try to do fp = open(filename, 'w'). But how do I get to know which user of my server is trying to create that file and how can I provide that user with appropriate permissions.I am working on AWS server.
My code for writing files is this:
with open(filename, 'w') as f_pointer:
os.chmod(filename, 777)
myfile = csv.writer(f_pointer)
myfile.writerow(columns)
myfile.writerows(rows)
Thanks

First check the file permission or owner , then use the property permission.
ls -l filename
Another, you should check if this user can create the filename in the directory .

The file is opened by the same user who is running the process. Now if the directory where you are creating the file or file you opening to write to are not writable by the user, then chmod will not work.
You'll have to chose the directory/file that is writable by the user.

Related

Chron - [Permission Denied] when I try to save & remove file from directory

Issue: Unable to save file in directory (/root/Notion/Image) when using Cron schedule
This is what my code is trying to do:
Check email
Download image attachment
Store in a directory - root/Notion/Image
Retrieve file path
The script is working when I run it manually in Google Cloud terminal. The problem is when I try to schedule it on Cron, it's unable to access the folder to save the file locally.
This is the error when the script failed and require permission:
Traceback (most recent call last):
File "Notion/test.py", line 121, in <module>
path = get_attachments(email.message_from_bytes(msg[0][1]))
File "Notion/test.py", line 47, in get_attachments
with open(filePath, 'wb') as f:
PermissionError: [Errno 13] Permission denied: '/root/Notion/Image/3.jpeg'
This is the code to retrieve attachment from email
def get_attachments(msg):
for part in msg.walk():
if part.get_content_maintype()=='multipart':
continue
if part.get('Content-Disposition') is None:
continue
fileName = part.get_filename()
if bool(fileName):
filePath = os.path.join(attachment_dir, fileName)
with open(filePath, 'wb') as f:
f.write(part.get_payload(decode=True))
return str(filePath)
Resolved:
The problem is that I shouldn't use root directory since it requires permission. I've changed it to home directory instead.
attachment_dir = '/home/dev_thomas_yang/folder_name/folder_name'
For people who needs to check their home direction, simply run this script.
from pathlib import Path
home= str(Path.home())
print(home)
Thanks Triplee for the patience to breakdown my issue despite my sloppy ways of presenting it!
The easiest fix hands down is to change the code so it doesn't try to write to /root. Have it write to the invoking user's home directory instead.
Your question doesn't show the relevant parts of the code, but just change attachment_dir so it's not an absolute path. Maybe separately take care of creating the directory if it doesn't already exist.
import pathlib
# ...
attachment_dir = pathlib.Path("cron/whatever/attachments").mkdir(parents=True, exist_ok=True)
# ...
for loop in circumstances:
get_attachments(something)
A better design altogether would be to have get_attachments accept the directory name as a parameter, so you can make this configurable from the code which calls it. Global variables are a nuisance and cause hard-to-debug problems because they hide information which is important for understanding the code, and tricky to change when you try to debug that code and don't know which parts of the code depend on the old value.

Access Denied to zipfile created using python

I was able to create a zip file using the below code:
import os
import zipfile
user = input('Please enter your ID:')
date = input('Please enter the date:')
os.chdir('C:/Users/'+user+'/Desktop/Files/')
name = 'Position_'+date+'_Global'
newzip = zipfile.ZipFile(name+'.zip', 'w', zipfile.ZIP_DEFLATED)
newzip.write(name+'.txt')
print(newzip.infolist())
newzip.close()
The code runs successfully, but I am facing access denied error while trying to open the zip file.
Compressed (zipped) Folders Error:
Windows cannot open the folder.
Access to the Compressed (zipped) Folder
'C:/Users/XXXXX/Desktop/Files/Position__Global.zip' is denied.
I am not sure what is causing the issue. Could you please check?
My office IT team debugged this:
The issue was due to restrictions on user privileges on my office PC. It occurs when you have user access but the python is being executed as Administrator. Then the file created by the administrator will not be available to be opened by common user.
Most of time, it happened at some application open the file and not closed. Remember to close the opened file in your script, or try to close your application when failed before you close the opened file.
import zipfile
newzip = zipfile.ZipFile('D:/test.zip', 'w', zipfile.ZIP_DEFLATED)
newzip.write('D:/test.txt')
print(newzip.infolist())
# newzip.close()

How to save a folder of txt files as a variable in python

I have a folder of txt folders that I want to import into python as a variable. Ideally, I want a variable 'profession_texts' where each txt file is an element in a list. This is what I have at the moment:
import os
profession_folder_path = '../fp/Updated/Profession/'
profession_files = os.listdir(profession_folder_path)
profession_texts = [open(profession_folder_path+file_name, encoding='utf-8').read() for file_name in profession_files]
print(profession_texts[0])
Yet, when running this script, I get the error:
PermissionError: [Errno 13] Permission denied: '../fp/Updated/Profession/Athlete'
So I have two problems. How do I get rid of this PermissionError? Once this error is resolved, will my code work for attaining my goal?
You no need to append file name with directory as (profession_folder_path+file_name). Use os.path.realpath(file_name) instead
import os
profession_folder_path = '../fp/Updated/Profession/'
profession_files = os.listdir(profession_folder_path)
profession_texts = [open(os.path.realpath(file_name)).read() for file_name in profession_files]
print(profession_texts[0])
and for permissions you need to have read permissions on file and execute permission on directory if you are using unix. Run below command:
chmod -R a+rx '../fp/Updated/Profession/'

Permission issue Python 3.4 apache

im have FLASK app with
www/FlaskApp/FlaskApp/init.py file with funtion
python file wut next contains
#app.route('/')
def hello():
file = open('myfile.txt', 'w+')
os.mknod("newfile.txt")
return render_template('page2.html')
but if im run site,its return error, in file log write
PermissionError: [Errno 13] Permission denied: 'myfile.txt'
im set permision 777 for all www directories
open FileZilla
right click on www dir, and set 777 permision
Why file dont create?
Not sure if this is an optimal solution, and I don't know enough about Flask as to tell you why the relative path isn't working (I would think that it would write the file where ever your python script was) but you could get it to work by using an environment variable to specify where to store your apps data. For instance:
import os
#app.route('/')
def open_file():
filename = os.path.join(os.environ['FLASK_APP_DATA'], 'myfile.txt')
print (filename)
file = open(filename, 'w+')
file.write("This is a test")
file.close()
Then you could have the environment variable set differently on your dev box and your prod box.

Permission Denied To Write To My Temporary File

I am attempting to create and write to a temporary file on Windows OS using Python. I have used the Python module tempfile to create a temporary file.
But when I go to write that temporary file I get an error Permission Denied. Am I not allowed to write to temporary files?! Am I doing something wrong? If I want to create and write to a temporary file how should should I do it in Python? I want to create a temporary file in the temp directory for security purposes and not locally (in the dir the .exe is executing).
IOError: [Errno 13] Permission denied: 'c:\\users\\blah~1\\appdata\\local\\temp\\tmpiwz8qw'
temp = tempfile.NamedTemporaryFile().name
f = open(temp, 'w') # error occurs on this line
NamedTemporaryFile actually creates and opens the file for you, there's no need for you to open it again for writing.
In fact, the Python docs state:
Whether the name can be used to open the file a second time, while the named temporary file is still open, varies across platforms (it can be so used on Unix; it cannot on Windows NT or later).
That's why you're getting your permission error. What you're probably after is something like:
f = tempfile.NamedTemporaryFile(mode='w') # open file
temp = f.name # get name (if needed)
Use the delete parameter as below:
tmpf = NamedTemporaryFile(delete=False)
But then you need to manually delete the temporary file once you are done with it.
tmpf.close()
os.unlink(tmpf.name)
Reference for bug: https://github.com/bravoserver/bravo/issues/111
regards,
Vidyesh
Consider using os.path.join(tempfile.gettempdir(), os.urandom(24).hex()) instead. It's reliable, cross-platform, and the only caveat is that it doesn't work on FAT partitions.
NamedTemporaryFile has a number of issues, not the least of which is that it can fail to create files because of a permission error, fail to detect the permission error, and then loop millions of times, hanging your program and your filesystem.
The following custom implementation of named temporary file is expanded on the original answer by Erik Aronesty:
import os
import tempfile
class CustomNamedTemporaryFile:
"""
This custom implementation is needed because of the following limitation of tempfile.NamedTemporaryFile:
> Whether the name can be used to open the file a second time, while the named temporary file is still open,
> varies across platforms (it can be so used on Unix; it cannot on Windows NT or later).
"""
def __init__(self, mode='wb', delete=True):
self._mode = mode
self._delete = delete
def __enter__(self):
# Generate a random temporary file name
file_name = os.path.join(tempfile.gettempdir(), os.urandom(24).hex())
# Ensure the file is created
open(file_name, "x").close()
# Open the file in the given mode
self._tempFile = open(file_name, self._mode)
return self._tempFile
def __exit__(self, exc_type, exc_val, exc_tb):
self._tempFile.close()
if self._delete:
os.remove(self._tempFile.name)
This issue might be more complex than many of you think. Anyway this was my solution:
Make use of atexit module
def delete_files(files):
for file in files:
file.close()
os.unlink(file.name)
Make NamedTemporaryFile delete=False
temp_files = []
result_file = NamedTemporaryFile(dir=tmp_path(), suffix=".xlsx", delete=False)
self.temp_files.append(result_file)
Register delete_files as a clean up function
atexit.register(delete_files, temp_files)
tempfile.NamedTemporaryFile() :
It creates and opens a temporary file for you.
f = open(temp, 'w') :
You are again going to open the file which is already open and that's why you are getting Permission Denied error.
If you really wants to open the file again then you first need to close it which will look something like this-
temp= tempfile.NamedTemporaryFile()
temp.close()
f = open(temp.name, 'w')
Permission was denied because the file is Open during line 2 of your code.
close it with f.close() first then you can start writing on your tempfile

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