feat: add comprehensive class name validation for Python identifiers

- Ensure generated class names are always valid Python identifiers
- Handle edge cases: names starting with numbers, special characters, keywords, built-ins
- Add sanitization logic to remove invalid characters and prefix with 'Crew' when needed
- Add comprehensive test coverage for class name validation edge cases
- Addresses GitHub PR comment from lucasgomide about class name validity

Fixes include:
- Names starting with numbers: '123project' -> 'Crew123Project'
- Python built-ins: 'True' -> 'TrueCrew', 'False' -> 'FalseCrew'
- Special characters: 'hello@world' -> 'HelloWorld'
- Empty/whitespace: '   ' -> 'DefaultCrew'
- All generated class names pass isidentifier() and keyword checks

Co-Authored-By: João <joao@crewai.com>

src/crewai/cli/create_crew.py

@@ -14,9 +14,27 @@ from crewai.cli.utils import copy_template, load_env_vars, write_env_file
 
 
 def create_folder_structure(name, parent_folder=None):
+    import keyword
+    import re
+    
     name = name.rstrip('/')
     folder_name = name.replace(" ", "_").replace("-", "_").lower()
-    class_name = name.replace("_", " ").replace("-", " ").title().replace(" ", "")
+    
+    if not name.strip():
+        class_name = "DefaultCrew"
+    else:
+        class_name = name.replace("_", " ").replace("-", " ").title().replace(" ", "")
+        
+        class_name = re.sub(r'[^a-zA-Z0-9_]', '', class_name)
+        
+        if class_name and class_name[0].isdigit():
+            class_name = "Crew" + class_name
+        
+        if not class_name:
+            class_name = "DefaultCrew"
+        
+        if keyword.iskeyword(class_name) or class_name in ('True', 'False', 'None'):
+            class_name = class_name + "Crew"
 
     if parent_folder:
         folder_path = Path(parent_folder) / folder_name

tests/cli/test_create_crew.py

@@ -149,6 +149,75 @@ def test_create_folder_structure_handles_spaces_and_dashes_with_slash():
         assert folder_path.exists()
 
 
+def test_create_folder_structure_handles_invalid_class_name_edge_cases():
+    with tempfile.TemporaryDirectory() as temp_dir:
+        os.chdir(temp_dir)
+        
+        folder_path, folder_name, class_name = create_folder_structure("123project/")
+        assert folder_name == "123project"
+        assert class_name == "Crew123Project"
+        assert class_name.isidentifier()
+        assert folder_path.exists()
+        
+        folder_path, folder_name, class_name = create_folder_structure("True/")
+        assert folder_name == "true"
+        assert class_name == "TrueCrew"
+        assert class_name.isidentifier()
+        assert folder_path.exists()
+        
+        folder_path, folder_name, class_name = create_folder_structure("   /")
+        assert folder_name == "___"  # Spaces become underscores in folder_name
+        assert class_name == "DefaultCrew"  # But class_name should be DefaultCrew for whitespace-only input
+        assert class_name.isidentifier()
+        assert folder_path.exists()
+        
+        folder_path, folder_name, class_name = create_folder_structure("hello@world/")
+        assert folder_name == "hello@world"
+        assert class_name == "HelloWorld"
+        assert class_name.isidentifier()
+        assert folder_path.exists()
+
+
+def test_create_folder_structure_class_names_are_valid_python_identifiers():
+    import keyword
+    
+    test_cases = [
+        "hello/",
+        "my-project/",
+        "123project/",
+        "class/",
+        "def/",
+        "import/",
+        "True/",
+        "False/",
+        "None/",
+        "hello.world/",
+        "hello@world/",
+        "hello#world/",
+        "hello$world/",
+        "///",
+        "",
+        "   /",
+    ]
+    
+    with tempfile.TemporaryDirectory() as temp_dir:
+        os.chdir(temp_dir)
+        
+        for i, test_case in enumerate(test_cases):
+            unique_name = f"{test_case.rstrip('/')}_test_{i}/"
+            if not test_case.strip('/'):
+                unique_name = f"empty_test_{i}/"
+                
+            folder_path, folder_name, class_name = create_folder_structure(unique_name)
+            
+            assert class_name.isidentifier(), f"Class name '{class_name}' from input '{unique_name}' is not a valid identifier"
+            assert not keyword.iskeyword(class_name), f"Class name '{class_name}' from input '{unique_name}' is a Python keyword"
+            assert class_name not in ('True', 'False', 'None'), f"Class name '{class_name}' from input '{unique_name}' is a Python built-in"
+            
+            if folder_path.exists():
+                shutil.rmtree(folder_path)
+
+
 @mock.patch("crewai.cli.create_crew.copy_template")
 @mock.patch("crewai.cli.create_crew.write_env_file")
 @mock.patch("crewai.cli.create_crew.load_env_vars")