Add re import when using regex pattern

Author: horejsek

CHANGELOG.txt

@@ -4,6 +4,7 @@
 * Fixed detecting when infinity is reached with multipleOf
 * Fixed that min/max items/lenght/properties can be float
 * Fixed that everything with empty `not` is invalid
+* Fixed missing re import when using regex pattern
 * Improved regexp for email format to comfort test suite
 * Improved regexp for date format to comfort test suite
 * Improved regexp for ipv4 format to comfort test suite

fastjsonschema/draft04.py

@@ -271,6 +271,7 @@ def generate_format(self):
                 self._generate_format(format_, format_ + '_re_pattern', format_regex)
             # Format regex is used only in meta schemas.
             elif format_ == 'regex':
+                self._extra_imports_lines = ['import re'] 
                 with self.l('try:', optimize=False):
                     self.l('re.compile({variable})')
                 with self.l('except Exception:'):