Merge branch '4_pre_commit_git_hook' into 'master'

Update pre-commit git hook and its documentation to clear executed cells from notebooks

Closes #4

See merge request formations/cpp/gettingstartedwithmoderncpp!36

5-UsefulConceptsAndSTL/1-ErrorHandling.ipynb

@@ -313,9 +313,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "metadata": {
-    "scrolled": true
-   },
+   "metadata": {},
    "outputs": [],
    "source": [
     "#include <iostream>\n",

CONTRIBUTING.md

-All contributions are welcome.
+# Contribution guide
 
-# Git hook
+All contributions are welcome, but please read this first.
+
+## Git hook
 
 If you intend to contribute, please install first the pre-commit hook:
 
@@ -8,9 +10,9 @@ If you intend to contribute, please install first the pre-commit hook:
 cp Scripts/pre-commit .git/hooks/pre-commit
 ````
 
-This hook ensure no notebook with executed cells is committed.
+This hook clears executed cells when committing a notebook.
 
-# Workflow
+## Workflow
 
 The project is led through an integration manager workflow, so when you have a contribution to share, just open a merge request.
 

README.md

@@ -120,3 +120,4 @@ A link to a BinderHub instance is given at the top of the project page; foresee
 ## For maintainers
 
 Informations related to CI are [here](CI.md).
+All contributions are welcome, but please read the [contribution guide](CONTRIBUTING.md) first.

Scripts/check_no_executed_cell.py

-import argparse
-import sys
-from typing import Optional
-from typing import Sequence
-
-
-def find_executed_cell(filename):
-    """Read the file and check whether there is a line with "execution_count" and a non null value."""
-    stream = open(filename, encoding="utf8", errors='ignore')
-
-    executed_cells = [line.strip("\n,\" ") for line in stream if "execution_count" in line and "null" not in line ] 
-
-    return len(executed_cells)
-
-
-
-def main(argv: Optional[Sequence[str]] = None) -> int:
-    """First argument in command line is expected to be a list of filenames
-    
-    As the purpose of this file is to be used as a pre-commit git hook, the typical list are all the files modified by the commit in progress.
-
-    If one or more file includes a cell that has been executed, the function returns 1 and print on screen the incriminated file(s).
-    """
-    parser = argparse.ArgumentParser()
-    parser.add_argument('filenames', nargs='*', help='Filenames to check.')
-    args = parser.parse_args(argv)
-
-    filenames_with_executed_cells = []
-
-    for filename in args.filenames:
-        if find_executed_cell(filename):
-            filenames_with_executed_cells.append(filename)
-
-    if filenames_with_executed_cells:
-        print("Commit rejected: the following files feature executed cells: \n\t- {}".format("\n\t- ".join(filenames_with_executed_cells)))
-        return 1
-    
-    return 0
-
-
-if __name__ == '__main__':
-    sys.exit(main())
\ No newline at end of file

Scripts/pre-commit

@@ -3,6 +3,12 @@
 # This file is expected to be use as pre-commit git hook; copy it in .git/hooks/
 
 file_list=`git diff --cached --diff-filter=ACM --name-only`
-root_dir=`git rev-parse --show-toplevel`
-/usr/bin/env python3 ${root_dir}/Scripts/check_no_executed_cell.py ${file_list}
 
+for file in ${file_list}
+do
+  if [ "${file##*.}" = "ipynb" ]; then
+    echo "Clear cells from ${file}"
+    jupyter nbconvert --clear-output --inplace ${file}
+    git add ${file}
+  fi
+done