Python全栈开发之Git

No.1 Git

特点

• 版本控制：可以解决多人同时开发的代码问题，也可以找回历史代码
• 分布式：Git是一个分布式版本控制系统，同一个Git仓库，可以分布到不同的机器上，首先会有一台计算机充当服务器，这台计算机7*24小时服务，其他计算机都是从这台计算机克隆一份代码到自己的计算机中，并且各自把各自的修改提交到服务器仓库里，也可以从服务器仓库拉取别人的提交

安装

sudo apt-get install git -y

No.2 版本创建与回退

使用

创建一个版本库

git init

创建一个版本

git add test.txt
git commit -m 'v1.0'

查看工作区状态

get status

查看版本记录

git log
git log --pretty=oneline 将每次提交放到一行显示
git log --pretty=oneline --graph 以图形化方式显示每次提交

版本回退

git reset --hard HEAD^ 其中HEAD表示当前最新版本，一个^表示回退一个版本，有几个^表示回退几个版本
git reset --hard HEAD~1 1表示回退一个版本，那么10就是回退10个版本
git reset --hard HEAD

查看操作记录

git reflog

工作区、暂存区、版本库

• 计算机中的目录就是一个工作区
• 工作区中有一个隐藏目录.git，就是版本库，版本库中存在了许多东西，其中最重要的是stage(暂存区)，还有一个是git为我们自动创建的第一个分支master，以及指向master的HEAD指针，因此第一个分支是master，所以当我们执行git commit的时候是向master分支上推送，git add 文件是将修改后的文件放到暂存区，git commit是将暂存区中的数据提交到工作区

管理修改

echo 'this is first line' >> test.txt
git add test.txt
echo 'this is first line' >> test.txt
git commit -m 'v1.1'
git status # 发现第二次修改test.txt文件后，并没有真正的加入到工作区，所以并没有提交到版本库
On branch master
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   test.txt

no changes added to commit (use "git add" and/or "git commit -a")

撤销修改

撤销对test.txt文件的修改

get checkout -- test.txt

如果要撤销暂存区的修改时

git reset HEAD test.txt

对比文件

对比工作区中的test.txt文件和版本库中的有什么不同

git diff test.txt HEAD -- test.txt

对比两个版本中test.txt文件的不同

git diff HEAD HEAD^ -- test.txt

删除文件

我们将目录中的test.txt删除，git知道我们删除了文件，但是工作区和版本库就不知道了，所以我们执行git status就可以知道哪些文件被删除了

rm -rf test.txt
git status

现在我们有两个选择，一是确定这个文件要被删除，二是确定这个文件误删

# 1.
git rm test.txt
git commit
# 2.
git checkout -- test.txt

No.4 分支管理

创建与合并

git把我们每次提交的版本形成一条时间线，这个时间线就是一个分支，目前，这个分支叫master，每次提交后HEAD指向master，master指向提交，每次提交，master都会向前移动一步，所以这条时间线越来越长，当我们创建分支slave后，HEAD指向slave，指向新提交，从此，再次提交就会将版本提交到slave分支，而master不变，当我们在salve分支上的工作完成了，就可以合并分支

• 查看分支 git branch
• 创建并切换分支 git checkout -b <name>
• 切换分支 git checkout <name>
• 合并分支 git merge <name>
• 删除分支 git branch -d <name>

解决冲突

合并也不是一帆风顺的，比如说，我在工作区中有一个test.txt文件，这个文件中没有任何数据，我在master分支中向第一行增加了一行数据，提交到版本库中，然后切换到slave，在这个文件中新增加了一行数据，然后提交到版本库中，再进行合并就会出现冲突

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git checkout -b slave
Switched to a new branch 'slave'

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ cat test.txt
master:the new code

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ vi test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ cat test.txt
master:the new code
slave:the new code

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git add test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git commit -m '1.2'
[slave 5035bfb] 1.2
 1 file changed, 1 insertion(+)

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git checkout master
Switched to branch 'master'

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ cat test.txt
master:the new code

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ vi test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ cat test.txt
master:the new code
master:the new code

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git add test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git commit -m '1.3'
[master e46f9b7] 1.3
 1 file changed, 2 insertions(+)

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git merge slave
Auto-merging test.txt
CONFLICT (content): Merge conflict in test.txt
Automatic merge failed; fix conflicts and then commit the result.

# 解决冲突
kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master|MERGING)
$ cat test.txt
master:the new code
<<<<<<< HEAD
master:the new code

=======
slave:the new code
>>>>>>> slave

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master|MERGING)
$ vi test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master|MERGING)
$ cat test.txt
master:the new code
slave:the new code

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master|MERGING)
$ git add test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master|MERGING)
$ git commit -m '1.4'
[master b252477] 1.4

分支管理策略

通常，合并分支时，git会尽可能的使用fast forward模式，但是有时候快速合并没有成功但是也没有冲突，这个时候会合并之后做一次新的提交

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ vi test1.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ cat test1.txt
add new code

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git add test1.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git commit -m '1.5'
[slave 5fa46e2] 1.5
 1 file changed, 1 insertion(+)
 create mode 100644 test1.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git checkout master
Switched to branch 'master'

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ vi test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ cat test.txt
master:the new code
slave:the new code
master:add new code

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git merge slave
Merge made by the 'recursive' strategy.
 test1.txt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 test1.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git log --pretty=oneline
bee1e463867f605f16c3fbad6a50ea36f4e0b20a (HEAD -> master) 合并slave分支
5fa46e2ec62346526554b04b62a468afbde0f9ba (slave) 1.5
b2524777899baab52783e1b49360fedc1e6a7e50 1.4
e46f9b7b5c379238ddca5db70746bc4f9f8c5edc 1.3
5035bfba43172b02bdbb7447fd9ebb018e6f49f5 1.2
2ae2bcac4258f41cb1a1e3a3a81a572be80c28f9 1.1
8d3dee945a68e5996d9c088a9769f43fc5c75228 1.0

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git log --pretty=oneline --graph
*   bee1e463867f605f16c3fbad6a50ea36f4e0b20a (HEAD -> master) 合并slave分支
|\
| * 5fa46e2ec62346526554b04b62a468afbde0f9ba (slave) 1.5
* |   b2524777899baab52783e1b49360fedc1e6a7e50 1.4
|\ \
| |/
| * 5035bfba43172b02bdbb7447fd9ebb018e6f49f5 1.2
* | e46f9b7b5c379238ddca5db70746bc4f9f8c5edc 1.3
|/
* 2ae2bcac4258f41cb1a1e3a3a81a572be80c28f9 1.1
* 8d3dee945a68e5996d9c088a9769f43fc5c75228 1.0

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git branch -d slave
Deleted branch slave (was 5fa46e2).

但是快速合并分支后删除分支会丢失掉分支信息，所以我们很多时候需要禁用快速合并

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git checkout -b slave
Switched to a new branch 'slave'
M       test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ vi test2.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git add test2.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git commit -m '1.6'
[slave 1e833e6] 1.6
 1 file changed, 2 insertions(+)
 create mode 100644 test2.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git checkout master
Switched to branch 'master'
M       test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git merge --no-ff -m '禁用快速合并' slave
Merge made by the 'recursive' strategy.
 test2.txt | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 test2.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git log --graph --pretty=oneline
*   cabeb0f4edc6617d27e1a7624be927a0f5f7da59 (HEAD -> master) 禁用快速合并
|\
| * 1e833e62109f3dd266883834bf11014d85c4a3dc (slave) 1.6
|/
*   bee1e463867f605f16c3fbad6a50ea36f4e0b20a 合并slave分支
|\
| * 5fa46e2ec62346526554b04b62a468afbde0f9ba 1.5
* |   b2524777899baab52783e1b49360fedc1e6a7e50 1.4
|\ \
| |/
| * 5035bfba43172b02bdbb7447fd9ebb018e6f49f5 1.2
* | e46f9b7b5c379238ddca5db70746bc4f9f8c5edc 1.3
|/
* 2ae2bcac4258f41cb1a1e3a3a81a572be80c28f9 1.1
* 8d3dee945a68e5996d9c088a9769f43fc5c75228 1.0

bug分支

软件开发中，出现bug是经常性的事情，在git中，每个bug可以通过一个临时分支来修复，修复后删除分支，假如突然出现一个bug就需要立即修复，但是该分支的工作还没有完成，没有完成就没办法进行提交，所以就用到了git中的保存现场功能(stash)

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git status
On branch master
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   test.txt

no changes added to commit (use "git add" and/or "git commit -a")

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git stash
Saved working directory and index state WIP on master: cabeb0f 禁用快速合并

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git status
On branch master
nothing to commit, working tree clean

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git checkout slave
Switched to branch 'slave'

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git checkout -b bug001
Switched to a new branch 'bug001'

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (bug001)
$ vi test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (bug001)
$ git add test.txt

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (bug001)
$ git commit -m 'bug001修复完成'
[bug001 aab106b] bug001修复完成
 1 file changed, 1 deletion(-)

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (bug001)
$ git checkout slave
Switched to branch 'master'

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git merge bug001
Merge made by the 'recursive' strategy.
 test.txt | 1 -
 1 file changed, 1 deletion(-)

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git branch -d bug001
Deleted branch bug001 (was aab106b).

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (slave)
$ git checkout master
Switched to branch 'master'

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git stash list
stash@{0}: WIP on master: cabeb0f 禁用快速合并

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git stash pop
gOn branch slave
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   test.txt

no changes added to commit (use "git add" and/or "git commit -a")
Dropped refs/stash@{0} (8fe9c203f75afc7929433faabc52e02a6d555ff4)

kernel@DESKTOP-67P59AO MINGW64 /d/Codes/Git/test (master)
$ git status
On branch slave
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   test.txt

no changes added to commit (use "git add" and/or "git commit -a")

No.5 使用GitHub

添加ssh账户

如果某台机器需要与GitHub进行交互，那么就要把这台机器的ssh公钥添加到GitHub账户上

1. 编辑.github文件，使用ssh-keygen -t rsa -C "邮箱地址"，生成ssh密钥

2. 点击账户头像后的下拉三角，选择settings，选择SSH and GPG keys选项，单击New SSH keys，复制id_rsa.pub文件里的内容，点击Add SSH key

克隆项目

git clone 项目地址

上传分支

git push origin 分支名称

跟踪远程分支

git branch --set-upstream-to=origin/slave master

当本地成功跟踪远程分支后，当修改代码后，只需要git push就可以将修改提交到远程

从远程分支拉取代码

git pull origin 分支名称