Skip to content

02 CreateRepo

A# Create a Repository

Let's work on creating our first git repository.

All shell commands will be prefixed with > All comments, text not meant to be parsed by the computer, is prefixed with #.

Create a git repository#

First create a directory for our project and cd into the directory 

> mkdir -v nyc-311
> cd nyc-311
The -v flag produces verbose output so you can see what happened after the invocation of the command.

Now lets initialize the git repository. All git commands start with git <verb>. To initialize the git repo for our project we invoke the command 

> git init
Let's look at the contents of our directory using the command ls -a 
> ls -a

.  ..  .git/
The -a flag tells the ls command to include hidden directories when displaying files. We can see that there is now a .git directory. Unless you really know what you are doing DO NOT EVER modify anything in this directory. If you delete this directory, the entire history of your project will be gone.

Make our first commit!!#

All good projects should have a README.md to describe the project. So let's start with that. Fire up you favorite text editor and name a file README.md.

Add something like this in your README: 

# Exploring 311 Calls in NYC

## Description

This repo is for an analysis of 311 calls in NYC using Python 3.4
The # are part of markdown syntax for designating headings.

Now let's look at the status of our repo using git status: 

> git status
On branch master

Initial commit

Untracked files:
  (use "git add <file>..." to include in what will be committed)

          README.md

          nothing added to commit but untracked files present (use "git add" to track)
We can see that git knows that we have added a file but it is untracked. What this means is that git knows that this file has been added but it is currently "untracked" by git. Like the command said let's use git add to track changes in the the file by invoking the command git add README.md. 
> git add README.md
Now lets look at the status of the repository by invoking the command git status again.

> git status

On branch master

Initial commit

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)

          new file:   README.md
Now that we have added the file it has been "staged" in the staging area. We can now make our first commit! 
> git commit
When you invoke this command an editor should pop-up and you have to leave a commit message. Good commit messages lead to a usable git log and separates the novice git users from the competent practitioners. Generally you should follow these guidelines in a commit message:

  1. First line is a one line summary of the commit that is in title case and less then 80 characters, written in the imperative voice.

  2. Second line should be blank.

  3. Third and subsequent lines should be more details of the commit.

Anyone can look at a commit and examine what was changed. The commit message is where you provide a context of what and why you did what you did in the project.

A good rule of thumb is If applied this commit will,

My commit message is the following: 

Checking in README file

* Added short description of the project
* Added python3 as a dependency

### Using Nano as a text editor

If you are using nano, to save your text use Ctrl-O, write a filename and to exit use Ctrl-X.

Now that we have made our first commit we can examine our log! 

> git log
The first line should output 
* commit aaf89fd77e9b43d99fe32823843a7519b2108c90
  Author: Clark Kent <clark.kent@dailyplanet.com>
  Date:   Sat Nov 05 13:45:11 2016 -0600

          Checking in README file

          * Added short description of the project
          * Added python3 as a dependency
The first line is a unique identifier of your commit. The second give information on who made the commit. The third line gives the date. The rest is the commit message.

To just get titles of commit messages you can use the following command 

> git log --oneline
Another useful command is 
> git log --oneline --graph --all --decorate

Some helpful commands#

Removing files via git allows them to be recovered. 

git rm FILENAME
git rm -r DIRECTORY
Renaming files can be done by moving a file and then adding it or you can use the following command: 
git mv OLD NEW
git rm and git mv will stage the changes that will ulimately need to be commited. That is it we have our first commit and repo! Next we are going to write some code!