added pre_gen hook with additional checks

cookiecutter.json

@@ -1,6 +1,6 @@
 {
     "new_wiki": "",
-    "wiki_name": "{{ cookiecutter.new_wiki|title|replace(' ', '')|replace('Wiki', '') }}",
+    "wiki_name": "{{ cookiecutter.new_wiki|title|replace(' ', '') }}",
     "directory_name": "{{ cookiecutter.wiki_name|lower }}",
     "url": "https://{{cookiecutter.directory_name}}.cpi.imtek.uni-freiburg.de/"
 }

hooks/pre_gen_project.py

@@ -0,0 +1,25 @@
+import re
+import sys
+from pathlib import Path
+
+MOIN_PATH = '/var/www/moin/wikis'
+MODULE_REGEX = r'^[_a-zA-Z][_a-zA-Z0-9]+$'
+
+module_name = '{{ cookiecutter.directory_name }}'
+
+if not re.match(MODULE_REGEX, module_name):
+    print('ERROR: %s is not a valid Python module name!' % module_name)
+    sys.exit(1)
+
+try:
+    import {{ cookiecutter.directory_name }}
+    print('ERROR: %s is an existing Python module!' % module_name)
+    sys.exit(2)
+except ModuleNotFoundError:
+    pass
+
+
+wiki_path = Path(MOIN_PATH) / module_name
+if wiki_path.exists():
+    print('ERROR: wiki %s already exists!' % module_name)
+    sys.exit(1)