Getting TypeError: __init__() missing 1 required positional argument: “on_delete” when trying to add parent table after child table with entries

I have two classes in my sqlite database, a parent table named Categorie and the child table called Article. I created first the child table class and addes entries. So first I had this:

class Article(models.Model):
    titre=models.CharField(max_length=100)
    auteur=models.CharField(max_length=42)
    contenu=models.TextField(null=True)
    date=models.DateTimeField(
        auto_now_add=True,
        auto_now=False,
        verbose_name="Date de parution"
    )

    def __str__(self):
        return self.titre

And after I have added parent table, and now my models.py looks like this:

from django.db import models

# Create your models here.
class Categorie(models.Model):
    nom = models.CharField(max_length=30)

    def __str__(self):
        return self.nom


class Article(models.Model):
    titre=models.CharField(max_length=100)
    auteur=models.CharField(max_length=42)
    contenu=models.TextField(null=True)
    date=models.DateTimeField(
        auto_now_add=True,
        auto_now=False,
        verbose_name="Date de parution"
    )
    categorie = models.ForeignKey("Categorie")

    def __str__(self):
        return self.titre

So when I run python manage.py makemigrations <my_app_name>, I get this error:

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "C:UserslislisAppDataLocalProgramsPythonPython35-32libsite-packagesdjango-2.0-py3.5.eggdjangocoremanagement\__init__.py", line 354, in execute_from_command_line
    utility.execute()
  File "C:UserslislisAppDataLocalProgramsPythonPython35-32libsite-packagesdjango-2.0-py3.5.eggdjangocoremanagement\__init__.py", line 330, in execute
    django.setup()
  File "C:UserslislisAppDataLocalProgramsPythonPython35-32libsite-packagesdjango-2.0-py3.5.eggdjango\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:UserslislisAppDataLocalProgramsPythonPython35-32libsite-packagesdjango-2.0-py3.5.eggdjangoapps
egistry.py", line 112, in populate
    app_config.import_models()
  File "C:UserslislisAppDataLocalProgramsPythonPython35-32libsite-packagesdjango-2.0-py3.5.eggdjangoappsconfig.py", line 198, in import_models
    self.models_module = import_module(models_module_name)
  File "C:UserslislisAppDataLocalProgramsPythonPython35-32libimportlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "C:UserslislisDjangomon_sitelogmodels.py", line 6, in <module>
    class Article(models.Model):
  File "C:UserslislisDjangomon_sitelogmodels.py", line 16, in Article
    categorie = models.ForeignKey("Categorie")
TypeError: __init__() missing 1 required positional argument: "on_delete"

I"ve seen some similar issues in stackoverflow, but it seems to not be the same problem: __init__() missing 1 required positional argument: 'quantity'

Getting TypeError: __init__() missing 1 required positional argument: "on_delete" when trying to add parent table after child table with entries __del__: Questions

import time
time.sleep(5)   # Delays for 5 seconds. You can also use a float value.

import time
while True:
    print("This prints once a minute.")
    time.sleep(60) # Delay for 1 minute (60 seconds).

from time import sleep
sleep(0.1) # Time in seconds

Getting TypeError: __init__() missing 1 required positional argument: "on_delete" when trying to add parent table after child table with entries __delete__: Questions

import os
os.remove("/tmp/<file_name>.txt")

import os
os.unlink("/tmp/<file_name>.txt")

file_to_rem = pathlib.Path("/tmp/<file_name>.txt")
file_to_rem.unlink()

#!/usr/bin/python
import os
myfile="/tmp/foo.txt"

## If file exists, delete it ##
if os.path.isfile(myfile):
    os.remove(myfile)
else:    ## Show an error ##
    print("Error: %s file not found" % myfile)

#!/usr/bin/python
import os

## Get input ##
myfile= raw_input("Enter file name to delete: ")

## Try to delete the file ##
try:
    os.remove(myfile)
except OSError as e:  ## if failed, report it back to the user ##
    print ("Error: %s - %s." % (e.filename, e.strerror))

Enter file name to delete : demo.txt
Error: demo.txt - No such file or directory.

Enter file name to delete : rrr.txt
Error: rrr.txt - Operation not permitted.

Enter file name to delete : foo.txt

shutil.rmtree()

#!/usr/bin/python
import os
import sys
import shutil

# Get directory name
mydir= raw_input("Enter directory name: ")

## Try to remove tree; if failed show an error using try...except on screen
try:
    shutil.rmtree(mydir)
except OSError as e:
    print ("Error: %s - %s." % (e.filename, e.strerror))

a = [1, 2, 3, 4]
b = a.index(6)

del a[b]
print(a)

Traceback (most recent call last):
  File "D:zjm_codea.py", line 6, in <module>
    b = a.index(6)
ValueError: list.index(x): x not in list

a = [1, 2, 3, 4]

try:
    b = a.index(6)
    del a[b]
except:
    pass

print(a)

>>> a = ["a", "b", "c", "d"]
>>> a.remove("b")
>>> print(a)
["a", "c", "d"]

>>> a = [10, 20, 30, 40, 20, 30, 40, 20, 70, 20]
>>> a = [x for x in a if x != 20]
>>> print(a)
[10, 30, 40, 30, 40, 70]