Updated to follow python style guide.

Removed underscores and extra lines.
Followed python code convention.

gen_err.py

@@ -2,7 +2,7 @@
 import random
 import re
 
-__action_pattern_map = {
+action_pattern_map = {
     'delete(': ("\(", ""),
     'delete)': ("\)", ""),
     'delete,': (",", ""),
@@ -26,8 +26,7 @@
     'replace,with;': (",", ";"),
 }
 
-
-__action_pattern_map_kw = {
+action_pattern_map_kw = {
     'deleteWhile': ("while", ""),
     'deleteElif': ("elif", ""),
     'deleteIf': ("if", ""),
@@ -48,63 +47,51 @@
     'replaceElifwithElseif': ("elif", "elseif"),
 }
 
-_actions = list(__action_pattern_map.keys())
-_actions_kw = list(__action_pattern_map_kw.keys())
+actions = list(action_pattern_map.keys())
+actions_kw = list(action_pattern_map_kw.keys())
 
 def corrupt_syntax(line):
-
     err_cnt = random.randint(0, 2)
     cnt = 0
-    np.random.shuffle(_actions)
-
-    for act in _actions:
+    np.random.shuffle(actions)
+    
+    for act in actions:
         if cnt > err_cnt:
             break
-
         else:
-            _patt = __action_pattern_map[act]   #value _patt[0], _patt[1]
-
-            positions = [m.span() for m in re.finditer(_patt[0], line)]
-
+            patt = action_pattern_map[act]   #value patt[0], patt[1]
+            positions = [m.span() for m in re.finditer(patt[0], line)]            
             if(len(positions) == 0):
                 continue
             else:
                 if len(positions) > 1: 
                     to_corrupt = np.random.randint(len(positions))
                 else: 
                     to_corrupt = 0
-
-                line = line[:positions[to_corrupt][0]] + _patt[1] + line[positions[to_corrupt][1]:]
+                line = line[:positions[to_corrupt][0]] + patt[1] + line[positions[to_corrupt][1]:]
         return line
 
 def corrupt_kw_typo(line):
-
     err_cnt = random.randint(0, 2)
     cnt = 0
-
-    np.random.shuffle(_actions_kw)
-
-    for act in _actions_kw:
+    np.random.shuffle(actions_kw)
+
+    for act in actions_kw:
         if cnt > err_cnt:
             break
-
         else:
-            _patt = __action_pattern_map_kw[act]   #value _patt[0], _patt[1]
-
-            positions = [m.span() for m in re.finditer(_patt[0], line)]
-
+            patt = action_pattern_map_kw[act]   #value patt[0], patt[1]
+            positions = [m.span() for m in re.finditer(patt[0], line)]
             if(len(positions) == 0):
                 continue
             else:
                 if len(positions) > 1: 
                     to_corrupt = np.random.randint(len(positions))
                 else: 
                     to_corrupt = 0
-
-                line = line[:positions[to_corrupt][0]] + _patt[1] + line[positions[to_corrupt][1]:]
+                line = line[:positions[to_corrupt][0]] + patt[1] + line[positions[to_corrupt][1]:]
     return line
 
-
 file1 = open('good.txt', 'r')
 file2 = open('bad.txt', 'w')
 
@@ -114,4 +101,4 @@ def corrupt_kw_typo(line):
     file2.write(final_line)
 
 file1.close()
-file2.close()
+file2.close()