util: Add mkdir_p from psamm-import

psamm/util.py

@@ -19,6 +19,8 @@
 
 from __future__ import unicode_literals
 
+import os
+import errno
 import re
 import math
 import subprocess
@@ -184,6 +186,15 @@ def git_try_describe(repo_path):
     return None
 
 
+def mkdir_p(path):
+    """Make directory path if it does not already exist."""
+    try:
+        os.makedirs(path)
+    except OSError as e:
+        if e.errno != errno.EEXIST or not os.path.isdir(path):
+            raise
+
+
 def convex_cardinality_relaxed(f, epsilon=1e-5):
     """Transform L1-norm optimization function into cardinality optimization.