gjbex · gjbex · Nov 25, 2019 · Nov 25, 2019
diff --git a/source-code/README.md b/source-code/README.md
@@ -29,6 +29,7 @@ to create it.  There is some material not covered in the presentation as well.
 1. `data-formats`: illustrates how to deal with data formats such as CSV
     files, binary data and XML.
 1. `hydra`: Facebook Hydra application framework illustration.
+1. `jinja`: illustration of how to use the jinja2 template library.
 1. `logging`: illustration of Python's logging facilities.
 1. `file-system`: illustrations of interacting with the operating system
     and the file system.

diff --git a/source-code/jinja/README.md b/source-code/jinja/README.md
@@ -0,0 +1,12 @@
+# Jinja
+
+Jinja2 is a templating library for Python that can be used for reporting,
+or for any coding task that boils down to filling out templates.
+
+## What is it?
+
+1. `reporting.py`: Python script that creates either a MarkDown or HTML format
+   report on randomly generated people.  The data reported is a person's ID,
+   year of birth and number of friends.
+1. `population/templates/report.html`: template for the HTML report.
+1. `population/templates/report.md`: template for the MarkDown report.
diff --git a/source-code/jinja/population/__init__.py b/source-code/jinja/population/__init__.py
diff --git a/source-code/jinja/population/templates/report.html b/source-code/jinja/population/templates/report.html
@@ -0,0 +1,23 @@
+<html>
+    <head>
+        <title>Report</title>
+    </head>
+    <body>
+        <h1>Report on people</h1>
+
+        <table>
+            <tr>
+                <th>Person ID</th>
+                <th>year of birth</th>
+                <th>number of friends</th>
+            </tr>
+            {% for person in people %}
+            <tr>
+                <td> {{ person['id'] }} </td>
+                <td> {{ person['birthyear'] }} </td>
+                <td> {{ person['nr_friends'] }} </td>
+            <tr>
+            {% endfor %}          
+        </table>
+    </body>
+</html>
diff --git a/source-code/jinja/population/templates/report.md b/source-code/jinja/population/templates/report.md
@@ -0,0 +1,7 @@
+# Report
+
+| person ID | year of birth | number of friends |
+|-----------|---------------|-------------------|
+{% for person in people %}
+| {{ '%-9s'|format(person['id']) }} | {{ '%13d'|format(person['birthyear']) }} | {{ '%17d'|format(person['nr_friends']) }} |
+{% endfor %}
diff --git a/source-code/jinja/reporting.py b/source-code/jinja/reporting.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+from argparse import ArgumentParser
+from jinja2 import Environment, PackageLoader
+import population
+import random
+import string
+import sys
+
+
+def generate_person():
+    person = {
+        'id':  ''.join(random.choices(string.ascii_letters, k=5)),
+        'birthyear': random.randint(1950, 2015),
+        'nr_friends': random.randint(0, 50),
+    }
+    return person
+
+def main():
+    arg_parser = ArgumentParser(description='generate random people')
+    arg_parser.add_argument('n', type=int, default=5, nargs='?',
+                            help='number of people to generate')
+    arg_parser.add_argument('--format', choices=['html', 'md'],
+                            default='md', help='output format, html or md')
+    arg_parser.add_argument('--seed', type=int, default=1234,
+                            help='seed for random number generator')
+    options = arg_parser.parse_args()
+    random.seed(options.seed)
+    people = [generate_person() for _ in range(options.n)]
+    environment = Environment(loader=PackageLoader('population', 'templates'),
+                              trim_blocks=True, lstrip_blocks=True)
+    template = environment.get_template('report.' + options.format)
+    print(template.render(people=people))
+
+if __name__ == '__main__':
+    status = main()
+    sys.exit(status)