pep8 blank lines fixes

flake8 --select W391,E302,E301,E304

autopep8 can't fix W391 even though it claims it can.
Fixed using a simple custom script.

weboob/tools/regex_helper.py

@@ -50,6 +50,7 @@ ESCAPE_MAPPINGS = {
     "Z": None,
 }
 
+
 class Choice(list):
     """
     Used to represent multiple possibilities at this point in a pattern string.
@@ -57,16 +58,19 @@ class Choice(list):
     code is clear.
     """
 
+
 class Group(list):
     """
     Used to represent a capturing group in the pattern string.
     """
 
+
 class NonCapture(list):
     """
     Used to represent a non-capturing group in the pattern string.
     """
 
+
 def normalize(pattern):
     """
     Given a reg-exp pattern, normalizes it to a list of forms that suffice for
@@ -222,6 +226,7 @@ def normalize(pattern):
 
     return zip(*flatten_result(result))
 
+
 def next_char(input_iter):
     """
     An iterator that yields the next character from "pattern_iter", respecting
@@ -242,6 +247,7 @@ def next_char(input_iter):
             continue
         yield representative, True
 
+
 def walk_to_end(ch, input_iter):
     """
     The iterator is currently inside a capturing group. We want to walk to the
@@ -262,6 +268,7 @@ def walk_to_end(ch, input_iter):
                 return
             nesting -= 1
 
+
 def get_quantifier(ch, input_iter):
     """
     Parse a quantifier from the input, where "ch" is the first character in the
@@ -298,6 +305,7 @@ def get_quantifier(ch, input_iter):
         ch = None
     return int(values[0]), ch
 
+
 def contains(source, inst):
     """
     Returns True if the "source" contains an instance of "inst". False,
@@ -311,6 +319,7 @@ def contains(source, inst):
                 return True
     return False
 
+
 def flatten_result(source):
     """
     Turns the given source sequence into a list of reg-exp possibilities and
@@ -363,4 +372,3 @@ def flatten_result(source):
         for i in range(len(result)):
             result[i] += piece
     return result, result_args
-