Patterns read from a .gitignore file in the same directory as the path, or in any parent directory, with patterns in the higher level files (up to the toplevel of the work tree) being overridden by those in lower level files down to the directory containing the file. These patterns match relative to the location of the .gitignore file. A project normally includes such .gitignore files in its repository, containing patterns for files generated as part of the project build.
也就是会读上一层以及上上一层直到toplevel的.gitignore
你在controllers目录下,先读本目录的.gitignore,没有就把上一层的.gitignore读下来。。也就是说相当于你在controllers目录下的.gitignore下加了一行
admin.py