setup django on docker - python-3.x

Question

I am new to docker and trying to steup my django project using docker first time.
I am following https://docs.docker.com/compose/django/
Below are the files and their conents that am using.
am using Ubuntu 16
Dockerfile
FROM python:3
ENV PYTHONUNBUFFERED 1
RUN mkdir /code
WORKDIR /code
COPY requirements.txt /code/
RUN pip install -r requirements.txt
COPY . /code/
docker-compose.yml
version: '3'
services:
db:
image: mysql
web:
build: .
command: python manage.py runserver 0.0.0.0:8000
volumes:
- .:/code
ports:
- "8000:8000"
depends_on:
- db
requirements.txt
Django>=2.0,<3.0
psycopg2>=2.7,<3.0
I ran the below command
docker-compose run web django-admin startproject composeexample .
I have doubt in the below output:
.....:~/docker_practice$ docker images -a
REPOSITORY TAG IMAGE ID CREATED SIZE
docker_practice_web latest be61fbfc4d9e 49 seconds ago 960MB
<none> <none> e73f8a4d68de 52 seconds ago 960MB
<none> <none> 7b597f9f4615 About a minute ago 918MB
<none> <none> 0eaf59a89be4 About a minute ago 918MB
<none> <none> cc42d26c3cfb About a minute ago 918MB
<none> <none> ae64e2080658 About a minute ago 918MB
python 3 02d2bb146b3b 11 days ago 918MB
mysql latest b8fd9553f1f0 12 days ago 445MB
.......:~/docker_practice$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker_practice_web latest be61fbfc4d9e 52 seconds ago 960MB
python 3 02d2bb146b3b 11 days ago 918MB
mysql latest b8fd9553f1f0 12 days ago 445MB
When I run "docker images -a" It display 5 images with name as
What this images are?
where does it coming from ?

Answer 1

the command docker images -a will show you also intermediate images, which is hidden in default using docker images
see this