Explicity return None

As per PEP 8.

See https://peps.python.org/pep-0008/

Author: Daverball

stdnum/be/bis.py

@@ -123,3 +123,4 @@ def get_gender(number):
     number = compact(number)
     if int(number[2:4]) >= 40:
         return nn.get_gender(number)
+    return None

stdnum/be/nn.py

@@ -184,6 +184,7 @@ def get_birth_date(number):
     year, month, day = _get_birth_date_parts(compact(number))
     if year and month and day:
         return datetime.date(year, month, day)
+    return None
 
 
 def get_gender(number):

stdnum/be/ssn.py

@@ -126,6 +126,7 @@ def guess_type(number):
     for mod in _ssn_modules:
         if mod.is_valid(number):
             return mod.__name__.rsplit('.', 1)[-1]
+    return None
 
 
 def format(number):
@@ -153,3 +154,4 @@ def get_gender(number):
     for mod in _ssn_modules:
         if mod.is_valid(number):
             return mod.get_gender(number)
+    return None

stdnum/de/handelsregisternummer.py

@@ -373,4 +373,4 @@ def check_offeneregister(number, timeout=30, verify=True):  # pragma: no cover (
         json = response.json()
         return dict(zip(json['columns'], json['rows'][0]))
     except (KeyError, IndexError) as e:  # noqa: F841
-        return  # number not found
+        return None  # number not found

stdnum/do/ncf.py

@@ -240,3 +240,4 @@ def check_dgii(rnc, ncf, buyer_rnc=None, security_code=None, timeout=30, verify=
             [x.text.strip() for x in result.findall('.//th') if x.text],
             [x.text.strip() for x in result.findall('.//td/span') if x.text]))
         return _convert_result(data)
+    return None

stdnum/do/rnc.py

@@ -153,7 +153,7 @@ def check_dgii(number, timeout=30, verify=True):  # pragma: no cover
     if result and 'GetContribuyentesResult' in result:
         result = result['GetContribuyentesResult']  # PySimpleSOAP only
     if result == '0':
-        return
+        return None
     result = [x for x in result.split('@@@')]
     return _convert_result(result[0])
 

stdnum/eu/vat.py

@@ -68,7 +68,7 @@ def _get_cc_module(cc):
     if cc == 'el':
         cc = 'gr'
     if cc not in MEMBER_STATES:
-        return
+        return None
     if cc == 'xi':
         cc = 'gb'
     if cc not in _country_modules:

stdnum/pk/cnic.py

@@ -63,6 +63,7 @@ def get_gender(number):
         return 'M'
     elif number[-1] in '2468':
         return 'F'
+    return None
 
 
 # Valid Province IDs

stdnum/util.py

@@ -229,7 +229,7 @@ def get_cc_module(cc, name):
         mod = __import__('stdnum.%s' % cc, globals(), locals(), [name])
         return getattr(mod, name, None)
     except ImportError:
-        return
+        return None
 
 
 # this is a cache of SOAP clients