Git, Docker, Python Package and Module

Git, Docker, Python Package and Module

• 1.
  LESSON SUMMARY OOP
• 2.
  Git is aversion control system. Distributed version control systems exist because these systems will "merge" changes together intelligently, enabling multiple developers to work on a project at the same time. There are a few distributed version control systems, including Mercurial and Bazzar. However, Git is by far the most popular. Git is a command-line tool we can access by typing git in the shell. The first step in using Git is to initialize a folder as a repository. A repository (or "repo") tracks multiple versions of the files in the folder, enabling collaboration. We can initialize a repository by typing git init inside the folder we want to use for our project.
• 3.
  The typical Gitworkflow involves adding files, making changes, and storing a checkpoint (or "snapshot") of those changes. These checkpoints are called commits. Instead of storing every file in every commit, Git stores the diff, or the things that change between commits. Every project is a sequence of commits. Commits give us a powerful way to merge the changes of multiple team members together. We can even restore the repository to an earlier checkpoint, or moment in time.
• 4.
  committed - Thecurrent version of the file has been added to a commit, and Git has stored it. staged - The file has been marked for inclusion in the next commit, but hasn't been committed yet (and Git hasn't stored it yet). You might stage one file before working on a second file, for example, then commit both files at the same time when you're done. modified - The file has been modified since the last commit, but isn't staged yet. After we make changes to a Git repository, we can run the git status command to check the state of each file within it. Any files that don't show up in git status are in the committed state (i.e., don't have unsaved changes). Files can have one of three states in Git:
• 5.
  Before we canmake our first commit, we need to tell Git who we are so it can store that information along with the commit. This step ensures that all of the members on a team can tell who made a certain commit. We can do this by running git config. We only need to run this command once per computer, because Git will save the information. Git needs two pieces of information about you -- your email address and your name. You can configure your email with: git config --global user.email "your.email@domain.com" You can configure your name with: git config --global user.name "Your name"
• 6.
  To make acommit, we use git commit -m "Commit message here". The -m flag indicates that we're adding a message, and the text in quotes that comes after it is the commit message itself. It's customary to make the commit message something informative, so if we do have to rewind or merge code, it's obvious what changes we made and when. we can use git diff to see all of the line differences between the current and previous version. We can scroll up and down with the arrow keys, and exit git diff with the q key. If we want to see the differences after we stage a file, we can use git diff --staged
• 7.
  We can pullup a repository's commit history using the git log command. This command will show us a list of all of the commits to the repository, in descending order by creation date. If the output is very long, it will allow us to scroll. We can scroll through the log with the up and down arrows, and use the q key to exit. We can use git log --stat to see more details about the commits in the git log output.
• 8.
  Command Getting started withGit: git Initializing a repo: git init Check the state of each file: git status Add files to staging area: git add Configure identity in Git: • Configure email git config --global user.email "your.email@domain.com" • Configure name git config --global user.name "Your name" Making a commit git commit -m "Commit message here" Viewing the diff • View the diff before staged git diff • View the diff after staged git diff --staged View repo's commit history git log
• 9.
  Docker is basicallyseen as a tool. It can package our applications and algorithms along with their dependencies. it makes it easy for us to replicate our code or our projects, allows us to run them in the cloud or in other environments, share them across teams, deploy containers to production and much more.
• 10.
  Docker Container A Dockercontainer is the same idea as a physical container--think of it like a box with an application in it. Inside the box, the application seems to have a computer all to itself: it has its own machine name and IP address, and it also has its own disk drive (Windows containers have their own Windows Registry too). Figure 2.2 shows how the app is boxed by the container.
• 11.
  The application insidethe box (container) can’t see anything outside the box, but the box is running on a computer, and that computer can also be running lots of other boxes. The applications in those boxes have their own separate environments (managed by Docker), but they all share the CPU and memory of the computer, and they all share the computer’s operating system
• 12.
  List all container dockercontainer ps to list running container or docker container ps -a to list all container
• 13.
  docker container inspectshows you all the details of a container:
• 14.
  Running a dockercontainer docker run [docker_image] You can run containers from locally stored Docker images. If you use an image that is not on your system, the software pulls it from the online registry.
• 15.
  Run a ContainerUnder a Specific Name docker container run --name [container_name] [docker_image] You can check whether you have successfully set a container name by displaying a list of all containers (running and stopped) with the command: docker ps -a
• 16.
  Stop and startcontainer docker container stop [CONTAINER_ID] docker container start [CONTAINER_ID]
• 17.
  Exec into arunning container Sometimes, we want to run another process insi. How can we do this? First, we need to know either the ID or the name of the container, and then we can define which process we want to run and how we want it to run docker exec -it [CONTAINER NAME/ID] bash The -i flag signifies that we want to run the additional process interactively, and -t tells Docker that we want it to provide us with a TTY (a Terminal emulator) for the command. Finally, the process we run is bash.
• 18.
  OOP Python Import Python codeis organized into both modules and packages. In Python, you use the import keyword to make code in one module available in another. Imports in Python are important for structuring your code effectively. Using imports properly will make you more productive, allowing you to reuse code while keeping your projects maintainable.
• 19.
  In practice, amodule usually corresponds to one .py file containing Python code. The true power of modules is that they can be imported and reused in other code. >>> import math >>> math.pi 3.141592653589793 In the first line, import math, you import the code in the math module and make it available to use. In the second line, you access the pi variable within the math module. math is part of Python’s standard library, which means that it’s always available to import when you’re running Python. Modules Package You can use a package to further organize your modules. Note that a package is still a module. As a user, you usually don’t need to worry about whether you’re importing a module or a package. The package will consist of the following directories and files: