git三个位置：本地硬盘（当前工作目录）—缓存区（stage/index)—版本区(.git)
总结：出现问题的原因——将workspace.xml文件提交到缓存区了，commit不了，导致update项目也失败；
思考背后的原因：workspace.xml不能提交到版本库，只能放在本地；
解决思路：
1）首先，删除缓存区里面存在的xml配置文件,但本地硬盘不删除，git rm --cached ./idea/workspace.xml
2)从缓存中移除文件——撤销之前将正常py文件提交到缓存区，git reset HEAD  biz/integration_ap/improved_feature_deal_shixin_svc.py
3)再git status检查一下，出现nothing to commit就表示git可以进行push和update了；
参考重要关键教程————Git详细使用教程链接：[Git详细使用教程](https://blog.csdn.net/tgbus18990140382/article/details/52886786)
4）退出git log，英文状态下按Q;
添加文件到缓存 git add
提交代码到本地仓库 git commit
从缓存中移除文件 git reset HEAD
从缓存以及工作目录删除文件 git rm
git rm 会将条目从缓存区中移除。这与 git reset HEAD 将条目取消缓存是有区别的。 
“取消缓存”的意思就是将缓存区恢复为我们做出修改之前的样子。
默认情况下，git rm file 会将文件从缓存区和你的硬盘中（工作目录）删除。
如果你要在工作目录中留着该文件，可以使用 git rm –cached： 

sc@sc-All-Series:~/PycharmProjects/risk-model$ git status
On branch 4.0.0-dev
Your branch and 'origin/4.0.0-dev' have diverged,
and have 2 and 5 different commits each, respectively.
  (use "git pull" to merge the remote branch into yours)

Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

    new file:   .idea/dataSources.ids
    new file:   .idea/dataSources.local.xml
    new file:   .idea/dataSources.xml
    new file:   .idea/workspace.xml

Unmerged paths:
  (use "git reset HEAD <file>..." to unstage)
  (use "git rm <file>..." to mark resolution)

    both deleted:       biz/integration_api/features_deal_shixin_svc.py
    both deleted:       biz/integration_api/improved_feature_deal_shixin_svc.py

Changes not staged for commit:
  (use "git add/rm <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

    deleted:    .idea/dataSources.ids
    deleted:    .idea/dataSources.local.xml
    deleted:    .idea/dataSources.xml
    modified:   .idea/workspace.xml

sc@sc-All-Series:~/PycharmProjects/risk-model$ rm .idea/workspace.xml
sc@sc-All-Series:~/PycharmProjects/risk-model$ 
查看有.idea/workspace.xml
还有一些已经删除的py文件；
首先git status;
然后git rm --cached .idea/workspace.xml  ，删除xml
然后git reset HEAD  biz/integration_api/improved_feature_deal_shixin_svc.py
然后再git status检查一下：
sc@sc-All-Series:~/PycharmProjects/risk-model$ git status
On branch 4.0.0-dev
Your branch and 'origin/4.0.0-dev' have diverged,
and have 2 and 5 different commits each, respectively.
  (use "git pull" to merge the remote branch into yours)
nothing to commit, working directory clean

就可以update 项目了；可以看图标！