DOC: Add excercise to README.md

README.md

@@ -23,13 +23,26 @@ where this file resides.
 Afterwards adjust the data model, the data and the crawler implementation in 
 `example_cfood.py` as you like.
 
+## Practice your crawling
+After executing `crawl.py` you'll notice that two new experiment records with a
+date and a result have been created. However, they are lacking the information
+about their project. As an excercise on your way towards developing your own
+crawler module, try to implement an project cfood that collects the project
+information from the directory name(s) within `data` and creates or updates a
+corresponding project record. Afterwards, extend `example_cfood.py` and
+`crawl.py` such that the project information is attached to the experiment
+records.
+
 ## Contributing
 
-Thank you very much to all contributers—[past, present](https://gitlab.com/caosdb/caosdb/-/blob/dev/HUMANS.md), and prospective ones.
+Thank you very much to all contributers—[past,
+present](https://gitlab.com/caosdb/caosdb/-/blob/dev/HUMANS.md), and prospective
+ones.
 
 ### Code of Conduct
 
-By participating, you are expected to uphold our [Code of Conduct](https://gitlab.com/caosdb/caosdb/-/blob/dev/CODE_OF_CONDUCT.md).
+By participating, you are expected to uphold our [Code of
+Conduct](https://gitlab.com/caosdb/caosdb/-/blob/dev/CODE_OF_CONDUCT.md).
 
 ## License
 

example_cfood.py

@@ -36,12 +36,15 @@ except ImportError:
 class ExampleCFood(AbstractFileCFood):
     @classmethod
     def get_re(cls):
-        # matches for example `data/2010_TestProject/2019-02-03/README.md`
+        # matches for example `data/2010_TestProject/2019-02-03/result.yml`
         # The following groups are created (values for the above example):
         # - project_identifier: 2010_TestProject
         # - project_year: 2010
         # - project_name: TestProject
         # - date: 2019-02-03
+        #
+        # Note that the project is not used in the following example (see
+        # excercise in the README.md).
 
         return (r".*/(?P<project_identifier>"
                 r"(?P<project_year>\d{4})_?(?P<project_name>((?!/).)*))/"