Optimize notebook validation

docs/notebook_validation.py

@@ -13,9 +13,11 @@
 import subprocess
 from shutil import which
 
-if which('jupyter') is None:
-    print("Please install jupyter, e.g. with `pip install notebook`.")
-    exit(1)
+
+def check_jupyter_installed():
+    if which('jupyter') is None:
+        print("Please install jupyter, e.g. with `pip install notebook`.")
+        exit(1)
 
 
 def read_available_backends():
@@ -26,15 +28,16 @@ def read_available_backends():
 
 def validate(notebook_filename, available_backends):
     with open(notebook_filename) as f:
-        lines = f.readlines()
-    for notebook_content in lines:
-        match = re.search('set_target[\\\s\(]+"(.+)\\\\"[)]', notebook_content)
-        if match and (match.group(1) not in available_backends):
-            return False
-    for notebook_content in lines:
-        match = re.search('--target ([^ ]+)', notebook_content)
-        if match and (match.group(1) not in available_backends):
-            return False
+        lines = f.read()
+    if any(
+            re.search(pattern, lines) for pattern in
+        ['set_target[\\\s\(]+"(.+)\\\\"[)]', '--target ([^ ]+)']):
+        matches = re.findall(
+            'set_target[\\\s\(]+"(.+)\\\\"[)]|--target ([^ ]+)', lines)
+        for match in matches:
+            backend = match[0] if match[0] else match[1]
+            if backend not in available_backends:
+                return False
     return True
 
 
@@ -75,6 +78,8 @@ def print_results(success, failed, skipped=[]):
 
 
 if __name__ == "__main__":
+    check_jupyter_installed()
+
     if len(sys.argv) > 1:
         notebook_filenames = sys.argv[1:]
         notebooks_success, notebooks_failed = ([] for i in range(2))