Adding error handling for YAML import.

1.  Moving all YAML library usage into 'util.py' via utility function.
2.  Wrapping 'import yaml' in error handling to report what library to install.

diff --git a/bin/lesson_check.py b/bin/lesson_check.py
index ef69f5e3f7d0329e0c3bb1800f1c417bfcf9387d..c123984aad2e325770098e9eb7721ed91129f5ae 100755 (executable)
--- a/bin/lesson_check.py
+++ b/bin/lesson_check.py
@@ -8,7 +8,6 @@ import sys
 import os
 import glob
 import json
-import yaml
 import re
 from optparse import OptionParser
 
@@ -131,8 +130,7 @@ def check_config(reporter, source_dir):
     """Check configuration file."""
 
     config_file = os.path.join(source_dir, '_config.yml')
-    with open(config_file, 'r') as reader:
-        config = yaml.load(reader)
+    config = load_yaml(config_file)
     reporter.check_field(config_file, 'configuration', config, 'kind', 'lesson')
 
 

diff --git a/bin/util.py b/bin/util.py
index 975560bfb71f2b459cd12f9ba6b8f56213585ce1..6af0a3317061d8663dafad9de41aec2156b7e597 100644 (file)
--- a/bin/util.py
+++ b/bin/util.py
@@ -1,8 +1,12 @@
 import sys
 import json
-import yaml
 from subprocess import Popen, PIPE
 
+try:
+    import yaml
+except ImportError:
+    print('Unable to import YAML module: please install PyYAML', file=sys.stderr)
+    sys.exit(1)
 
 class Reporter(object):
     """Collect and report errors."""
@@ -106,3 +110,13 @@ def split_metadata(path, text):
             sys.exit(1)
 
     return metadata_raw, metadata_yaml, text
+
+
+def load_yaml(filename):
+    """
+    Wrapper around YAML loading so that 'import yaml' and error
+    handling is only needed in one place.
+    """
+
+    with open(filename, 'r') as reader:
+        return yaml.load(reader)

diff --git a/bin/workshop_check.py b/bin/workshop_check.py
index 3b6f6f2e7fbf4d8fd01068c5a578fa5d3d9a2aa2..d018b78906171d3427350ad1dcba0d627435effd 100755 (executable)
--- a/bin/workshop_check.py
+++ b/bin/workshop_check.py
@@ -7,7 +7,6 @@ docstrings on the checking functions for a summary of the checks.
 import sys
 import os
 import re
-import yaml
 from datetime import date
 from util import Reporter, split_metadata
 
@@ -373,13 +372,19 @@ def check_config(reporter, filename):
     Check YAML configuration file.
     """
 
-    with open(filename, 'r') as reader:
-        config = yaml.load(reader)
+    config = load_yaml(filename)
 
-    reporter.check(config['kind'] == 'workshop',
+    kind = config.get('kind', None)
+    reporter.check(kind == 'workshop',
                    filename,
-                   'Not configured as a workshop: found "{0}" instead',
-                   config['kind'])
+                   'Missing or unknown kind of event: {0}',
+                   kind)
+
+    carpentry = config.get('carpentry', None)
+    reporter.check(carpentry in ('swc', 'dc'),
+                   filename,
+                   'Missing or unknown carpentry: {0}',
+                   carpentry)
 
 
 def main():