refactor: refactor unnecessary else / elif when if block has a …

…`return` statement

The use of `else` or `elif` becomes redundant and can be dropped if the last statement under the leading `if` / `elif` block is a `return` statement.
In the case of an `elif` after `return`, it can be written as a separate `if` block.
For `else` blocks after `return`, the statements can be shifted out of `else`. Please refer to the examples below for reference.

Refactoring the code this way can improve code-readability and make it easier to maintain.

gui/login2.py

@@ -26,10 +26,9 @@ def pwd_verify(user, password):
                 'data': json_response['data'],
                 'msg': json_response['errmsg']
                 }
-    else:
-        return {'success': 'False',
-                'msg': json_response['errmsg']
-                }
+    return {'success': 'False',
+            'msg': json_response['errmsg']
+            }
 
 
 def login(data):

gui/login2_sms.py

@@ -29,10 +29,9 @@ def sms_verify(phone_num, sms_code, zone_code):
                 'data': json_response['data'],
                 'msg': json_response['errmsg']
                 }
-    else:
-        return {'success': False,
-                'msg': json_response['errmsg']
-                }
+    return {'success': False,
+            'msg': json_response['errmsg']
+            }
 
 
 def login(data):

main.py

@@ -32,12 +32,11 @@ def set_global_variable(data):
 def perform_login(credentials):
     if credentials['pwdlogin'] == 'True':
         return login2(credentials['usrname'], credentials['pwd'])
-    else:
-        smscredential = login1_sms(credentials['phonenum'])
-        if smscredential['pwdlogin'] == 'False':
-            return login2_sms(smscredential['phonenum'], smscredential['code'], smscredential['zonecode'])
-        if smscredential['pwdlogin'] == 'True':
-            return perform_login(login1(str(smscredential['phonenum'])))
+    smscredential = login1_sms(credentials['phonenum'])
+    if smscredential['pwdlogin'] == 'False':
+        return login2_sms(smscredential['phonenum'], smscredential['code'], smscredential['zonecode'])
+    if smscredential['pwdlogin'] == 'True':
+        return perform_login(login1(str(smscredential['phonenum'])))
 
 
 def login():