Error nonetype object is not iterable симс 4

На стадии ввода имени в тг боте выдает ошибку:
for row in result:
TypeError: ‘NoneType’ object is not iterable

Код db:

import sqlite3
class Database:
    def __init__(self, db_file):
        self.connection = sqlite3.connect(db_file)
        self.cursor = self.connection.cursor()
    def add_user(self, user_id):
        with self.connection:
             return self.cursor.execute("INSERT INTO 'users' ('user_id') VALUES (?)",(user_id,))

    def user_exist(self, user_id):
        with self.connection:
            result = self.cursor.execute("SELECT * FROM 'users' WHERE 'user_id' = ?",(user_id,)).fetchall()
            return bool(len(result))

    def set_nickname(self,user_id,nickname):
        with self.connection:
            return self.cursor.execute("UPDATE 'users' SET 'nickname' = ? WHERE 'user_id' = ?",(nickname,user_id))

    def get_signup(self,user_id):
        with self.connection:
            result = self.cursor.execute("SELECT 'signup' FROM 'users' WHERE 'user_id' = ?", (user_id,)).fetchone()
            for row in result:
                signup = str(row[0])
                return signup

    def set_signup(self,user_id, signup):
        with self.connection:
            return self.cursor.execute("UPDATE 'users' SET 'signup' = ? WHERE 'user_id' = ?",(signup,user_id))

Код main:

import logging
from aiogram import Bot, Dispatcher, executor, types
import markups as nav
from db import Database

TOKEN = "5103821559:AAGL20hGYw8wUvBdu7u_vNeUQlhVxjmQIQs"

logging.basicConfig(level = logging.INFO)

bot = Bot(token = TOKEN)
dp = Dispatcher(bot)

db = Database('database.db')

@dp.message_handler(commands = ['start'])
async def start(message: types.Message):
    if(not db.user_exist(message.from_user.id)):
        db.add_user(message.from_user.id)
        await bot.send_message(message.from_user.id, "Укажите ваш ник")
    else:
        await bot.send_message(message.from_user.id, "Вы уже зарегистрированы", reply_markup = nav.mainMenu)

@dp.message_handler()
async def bot_message(message: types.Message):
    if message.chat.type == 'private':
        if message.text == 'Профиль':
            pass
        else:
            if db.get_signup(message.from_user.id) == "setnickname":
                if len(message.text) > 15:
                    await bot.send_message(message.from_user.id, "Никнейм не должен превышать 15 символов")
                elif '@' in message.text or '/' in message.text:
                    await bot.send_message(message.from_user.id, "Вы ввели запрещеный символ")
                else:
                    db.set_nickname(message.from_user.id, message.text)
                    db.set_signup(message.from_user.id, "done")
                    await bot.send_message(message.from_user.id, "Регистрация прошла успешно", reply_markup = nav.mainMenu)
            else:
                await bot.send_message(message.from_user.id, "Я не понял")

if __name__ == "__main__":
    executor.start_polling(dp, skip_updates = True)

Прежде чем писать в тему, прочтите:

При описании своей проблемы, во избежание ненужной выясняловки, занимающее немало времени и места, пишите сразу:

1. Тип ОС (Windows XX, MacOS), разрядность ОС

Версия Sims 4

Указание какая игра, лицензия, пиратка, Legacy (некоторые моды, например BD, не поддерживают такую версию)

Версии основных модов с датой их выпуска

WickedWhims (WW)

Nisa’s Wicked Perversions (NWP)

Basemental Drugs  (BD)

McCmdCenter (MCCC)

Указать, имеется ли DeviousDesires (Wicked Whims Kinky, CNWW более не существует)

Указать, играете ли вы со включенным антивирусником AWAST

Указать после обновления 1.58, прогоняли ли вы свои моды через S4S на тест «Slot195» 

Если вопрос касается конкретного мода, указывайте его версию и дату

2. Полное описание проблемы,

желательно прикладывать графику, на которой видна ваша проблема, это поможет быстрее ее понять.

3. Приложить lastException.txt (в дальнейшем LE), если таковой имеется, а также WickedWhims.log, BE-ExceptionReport.html, (находятся в корне папки Electronic ArtsThe Sims 4), BE-PatchScannerReport.html, (последний находится в папке The Sims 4ModsTMEX-Settings), mc_lastexception.html, (находится в одной папке с модом МССС ) и др логи. Логи паковать в архиве rar, zip, 7z, (размещать в посту сам текст LE, в виду некоторых проблем, не надо) и прикладывать к посту.

Просьба отписываться, если проблема решилась и каким образом. Это поможет другим.

Примечание: обладателям Legacy убедиться, что ваши моды поддерживают Legacy

Правило: 

Если играешь с DeviousDesires и видишь ошибки, прежде чем писать сюда, первым делом удали, этот самый глючный из всех, мод вместе с его библиотекой.

Скорей всего, у вас все наладится.

——————————————————————————————————————

Прежде чем давать описание проблемы прочитайте про типовые проблемы, (имеющие наиболее частые однотипные вопросы) см. скрытый текст.

— прежде чем писать о своей проблеме, проверьте ее на так называемом чистом сохранении. Создание его: старую игровую папку переименовать, например, The Sims 41. Игра при запуске БЕЗ МОДОВ создаст новую папку The Sims 4. Создаете семью, сохраняетесь и выходите. Это называется ЧИСТОЕ СОХРАНЕНИЕ. Именно оно поможет легко вычислить глюки и проблемы с любым модом или папкой модов. 

— после любых изменений в модах и допах, не забывать удалять файл кеша localthumbcache. Он содержит остатки переменных от предыдущих модов, а также допы. Допы кешируются целиком для более быстрого их чтения.

Чистка сейвов от Турбо

————————————————————————————————————————————————————————

После выхода патча 1.52 поломались некоторые прически и черты характера. При этом возникают проблемы с самой игрой, вплоть до краха.

Также возникла проблема бликования персонажей при любом параметре отображения персонажей ниже «Самого высокого». Проблему решать удалением поиска и удаления допов, поскольку они кроме отображения, могут вызывать случайные оранжевые окна и образование LE.

Способ решения вопроса с бликованием персонажей см. подробней тут.

После выхода патча 1.58 поломались элементы декора мебели, объектов. При этом возникают проблемы с самой игрой, вплоть до краха.

Метод поиска сломанных допов Slot195

Проблема с кастомными стульями, на которые симы отказываются садиться, только на игровые от ЕА.

Метод дихотомии (50/50) поиска мода/допа, вызывающего проблемы.

Другие названия метода, половинного деления, 50/50, возможны другие.

Существует более сложный способ выявления и удаления плохих CC, (искажающих облика сима, отсутствие лица, крест вместо одежды и прочее), но он предполагает использование Sims 4 Tray Importer.

________________________________________________________________________________________________________________________________________

Черный список (ЧС)

Список глючных допов и модов находится в скрытом тексте:

Примечание:

список составляется на основе сообщений участников и названия даются так, как есть в их сообщениях.

При появлении обновлений модов или допов, просьба сообщать для внесения их сюда. 

____________________________________________________________________________________________________________________________________________

—————————————————————————————————————————————————

Методические материалы по Sims 4

(см. скрытый текст)

Текст будет дополняться.

<report><version>2</version><sessionid>d5f54df10e8f16755beb3aae</sessionid><type>desync</type><sku>ea.maxis.sims4_64.15.pc</sku><createtime>2018-11-13 22:34:25</createtime><buildsignature>Local.Unknown.Unknown.1.47.49.1020-1.200.000.373.Release</buildsignature><categoryid>posture_graph.py:4094</categoryid><desyncid>d5f54df10e8f16755beb3aae</desyncid><systemconfig/><screenshot/><desyncdata>TODO: Exception thrown during Sim reset, possibly we should be kicking the Sim out of the game. (TypeError: ‘NoneType’ object is not iterable) Traceback (most recent call last): File «T:InGameGameplayScriptsCoresims4commands.py», line 369, in invoke_command File «T:InGameGameplayScriptsServerserver_commandsinteraction_commands.py», line 788, in select_choice File «T:InGameGameplayScriptsServerserverclient.py», line 265, in select_interaction File «T:InGameGameplayScriptsServerobjectsbase_object.py», line 266, in reset File «T:InGameGameplayScriptsServerservicesreset_and_delete_service.py», line 301, in trigger_reset File «T:InGameGameplayScriptsServerservicesreset_and_delete_service.py», line 419, in start_processing File «T:InGameGameplayScriptsServerservicesreset_and_delete_service.py», line 443, in _process File «T:InGameGameplayScriptsServerservicesreset_and_delete_service.py», line 553, in _process_one_record File «T:InGameGameplayScriptsServerserverclient.py», line 257, in select_interaction File «T:InGameGameplayScriptsServerinteractionschoices.py», line 258, in select File «T:InGameGameplayScriptsServerinteractionsaop.py», line 236, in test_and_execute File «T:InGameGameplayScriptsServerinteractionsaop.py», line 224, in execute File «T:InGameGameplayScriptsServerinteractionsaop.py», line 212, in execute_interaction File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 1331, in append File «T:InGameGameplayScriptsLibcontextlib.py», line 119, in __exit__ File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 878, in _head_change_watcher File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 962, in _get_head File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 339, in get_next_unblocked_interaction File «T:InGameGameplayScriptsServerinteractionsbasesuper_interaction.py», line 2416, in get_sims_with_invalid_paths File «T:InGameGameplayScriptsServerinteractionsbasesuper_interaction.py», line 2380, in _generate_connectivity File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 1457, in compute_transition_connectivity File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 1504, in run_transitions File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3361, in _build_transitions File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3152, in _build_and_log_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3214, in _build_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 2692, in get_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 2870, in _get_transitions_for_sim File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 5718, in generate_connectivity_handles File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 5531, in _get_segmented_path_connectivity_handles File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 545, in generate_right_paths File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 4139, in _right_path_gen File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 679, in _shortest_path_gen File «T:InGameGameplayScriptsCorealgos.py», line 121, in shortest_path_gen File «T:InGameGameplayScriptsCorealgos.py», line 121, in &lt;listcomp&gt; File «T:InGameGameplayScriptsCorecaches.py», line 281, in __missing__ File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 4094, in heuristic_fn_right File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 3778, in _get_destination_locations_for_estimate File «T:InGameGameplayScriptsServerobjectspoolspool_seat.py», line 279, in _cache_and_return_position_and_routing_surface_for_posture ValueError: not enough values to unpack (expected 2, got 0) During handling of the above exception, another exception occurred: Traceback (most recent call last): File «T:InGameGameplayScriptsServersimssim.py», line 1563, in on_reset_internal_state File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 1433, in on_reset File «T:InGameGameplayScriptsLibcontextlib.py», line 112, in __enter__ File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 865, in _head_change_watcher File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 947, in get_head File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 962, in _get_head File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 339, in get_next_unblocked_interaction File «T:InGameGameplayScriptsServerinteractionsbasesuper_interaction.py», line 2416, in get_sims_with_invalid_paths File «T:InGameGameplayScriptsServerinteractionsbasesuper_interaction.py», line 2380, in _generate_connectivity File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 1457, in compute_transition_connectivity File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 1504, in run_transitions File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3361, in _build_transitions File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3152, in _build_and_log_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3214, in _build_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 2692, in get_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 2870, in _get_transitions_for_sim File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 5718, in generate_connectivity_handles File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 5531, in _get_segmented_path_connectivity_handles File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 545, in generate_right_paths File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 4139, in _right_path_gen File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 679, in _shortest_path_gen File «T:InGameGameplayScriptsCorealgos.py», line 121, in shortest_path_gen File «T:InGameGameplayScriptsCorealgos.py», line 121, in &lt;listcomp&gt; File «T:InGameGameplayScriptsCorecaches.py», line 281, in __missing__ File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 4094, in heuristic_fn_right TypeError: ‘NoneType’ object is not iterable rtim=0</desyncdata></report>
<report><version>2</version><sessionid>d5f54df10e8f16755beb3aae</sessionid><type>desync</type><sku>ea.maxis.sims4_64.15.pc</sku><createtime>2018-11-13 22:34:25</createtime><buildsignature>Local.Unknown.Unknown.1.47.49.1020-1.200.000.373.Release</buildsignature><categoryid>posture_graph.py:4094</categoryid><desyncid>d5f54df10e8f16755beb3aae</desyncid><systemconfig/><screenshot/><desyncdata>[sscholl] Exception processing ResetRecord:&lt;, reason:ResetReason.RESET_ON_ERROR, stage:_Stage.INTERNAL_STATE_RESET, being_processed:True, source:None, cause:Exception while selecting interaction from the pie menu.. This will result in a partially reset object (TypeError: ‘NoneType’ object is not iterable) Traceback (most recent call last): File «T:InGameGameplayScriptsCoresims4commands.py», line 369, in invoke_command File «T:InGameGameplayScriptsServerserver_commandsinteraction_commands.py», line 788, in select_choice File «T:InGameGameplayScriptsServerserverclient.py», line 265, in select_interaction File «T:InGameGameplayScriptsServerobjectsbase_object.py», line 266, in reset File «T:InGameGameplayScriptsServerservicesreset_and_delete_service.py», line 301, in trigger_reset File «T:InGameGameplayScriptsServerservicesreset_and_delete_service.py», line 419, in start_processing File «T:InGameGameplayScriptsServerservicesreset_and_delete_service.py», line 443, in _process File «T:InGameGameplayScriptsServerserverclient.py», line 257, in select_interaction File «T:InGameGameplayScriptsServerinteractionschoices.py», line 258, in select File «T:InGameGameplayScriptsServerinteractionsaop.py», line 236, in test_and_execute File «T:InGameGameplayScriptsServerinteractionsaop.py», line 224, in execute File «T:InGameGameplayScriptsServerinteractionsaop.py», line 212, in execute_interaction File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 1331, in append File «T:InGameGameplayScriptsLibcontextlib.py», line 119, in __exit__ File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 878, in _head_change_watcher File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 962, in _get_head File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 339, in get_next_unblocked_interaction File «T:InGameGameplayScriptsServerinteractionsbasesuper_interaction.py», line 2416, in get_sims_with_invalid_paths File «T:InGameGameplayScriptsServerinteractionsbasesuper_interaction.py», line 2380, in _generate_connectivity File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 1457, in compute_transition_connectivity File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 1504, in run_transitions File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3361, in _build_transitions File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3152, in _build_and_log_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3214, in _build_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 2692, in get_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 2870, in _get_transitions_for_sim File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 5718, in generate_connectivity_handles File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 5531, in _get_segmented_path_connectivity_handles File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 545, in generate_right_paths File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 4139, in _right_path_gen File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 679, in _shortest_path_gen File «T:InGameGameplayScriptsCorealgos.py», line 121, in shortest_path_gen File «T:InGameGameplayScriptsCorealgos.py», line 121, in &lt;listcomp&gt; File «T:InGameGameplayScriptsCorecaches.py», line 281, in __missing__ File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 4094, in heuristic_fn_right File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 3778, in _get_destination_locations_for_estimate File «T:InGameGameplayScriptsServerobjectspoolspool_seat.py», line 279, in _cache_and_return_position_and_routing_surface_for_posture ValueError: not enough values to unpack (expected 2, got 0) During handling of the above exception, another exception occurred: Traceback (most recent call last): File «T:InGameGameplayScriptsServerservicesreset_and_delete_service.py», line 553, in _process_one_record File «T:InGameGameplayScriptsServersimssim.py», line 1563, in on_reset_internal_state File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 1433, in on_reset File «T:InGameGameplayScriptsLibcontextlib.py», line 112, in __enter__ File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 865, in _head_change_watcher File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 947, in get_head File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 962, in _get_head File «T:InGameGameplayScriptsServerinteractionsinteraction_queue.py», line 339, in get_next_unblocked_interaction File «T:InGameGameplayScriptsServerinteractionsbasesuper_interaction.py», line 2416, in get_sims_with_invalid_paths File «T:InGameGameplayScriptsServerinteractionsbasesuper_interaction.py», line 2380, in _generate_connectivity File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 1457, in compute_transition_connectivity File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 1504, in run_transitions File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3361, in _build_transitions File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3152, in _build_and_log_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 3214, in _build_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 2692, in get_transitions_for_sim File «T:InGameGameplayScriptsServerposturestransition_sequence.py», line 2870, in _get_transitions_for_sim File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 5718, in generate_connectivity_handles File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 5531, in _get_segmented_path_connectivity_handles File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 545, in generate_right_paths File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 4139, in _right_path_gen File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 679, in _shortest_path_gen File «T:InGameGameplayScriptsCorealgos.py», line 121, in shortest_path_gen File «T:InGameGameplayScriptsCorealgos.py», line 121, in &lt;listcomp&gt; File «T:InGameGameplayScriptsCorecaches.py», line 281, in __missing__ File «T:InGameGameplayScriptsServerposturesposture_graph.py», line 4094, in heuristic_fn_right TypeError: ‘NoneType’ object is not iterable rtim=0</desyncdata></report>

Explanation of error: ‘NoneType’ object is not iterable

In python2, NoneType is the type of None. In Python3 NoneType is the class of None, for example:

>>> print(type(None))     #Python2
<type 'NoneType'>         #In Python2 the type of None is the 'NoneType' type.

>>> print(type(None))     #Python3
<class 'NoneType'>        #In Python3, the type of None is the 'NoneType' class.

Iterating over a variable that has value None fails:

for a in None:
    print("k")     #TypeError: 'NoneType' object is not iterable

Python methods return NoneType if they don’t return a value:

def foo():
    print("k")
a, b = foo()      #TypeError: 'NoneType' object is not iterable

You need to check your looping constructs for NoneType like this:

a = None 
print(a is None)              #prints True
print(a is not None)          #prints False
print(a == None)              #prints True
print(a != None)              #prints False
print(isinstance(a, object))  #prints True
print(isinstance(a, str))     #prints False

Guido says only use is to check for None because is is more robust to identity checking. Don’t use equality operations because those can spit bubble-up implementationitis of their own. Python’s Coding Style Guidelines — PEP-008

NoneTypes are Sneaky, and can sneak in from lambdas:

import sys
b = lambda x : sys.stdout.write("k") 
for a in b(10): 
    pass            #TypeError: 'NoneType' object is not iterable 

NoneType is not a valid keyword:

a = NoneType     #NameError: name 'NoneType' is not defined

Concatenation of None and a string:

bar = "something"
foo = None
print foo + bar    #TypeError: cannot concatenate 'str' and 'NoneType' objects

What’s going on here?

Python’s interpreter converted your code to pyc bytecode. The Python virtual machine processed the bytecode, it encountered a looping construct which said iterate over a variable containing None. The operation was performed by invoking the __iter__ method on the None.

None has no __iter__ method defined, so Python’s virtual machine tells you what it sees: that NoneType has no __iter__ method.

This is why Python’s duck-typing ideology is considered bad. The programmer does something completely reasonable with a variable and at runtime it gets contaminated by None, the python virtual machine attempts to soldier on, and pukes up a bunch of unrelated nonsense all over the carpet.

Java or C++ doesn’t have these problems because such a program wouldn’t be allowed to compile since you haven’t defined what to do when None occurs. Python gives the programmer lots of rope to hang himself by allowing you to do lots of things that should cannot be expected to work under exceptional circumstances. Python is a yes-man, saying yes-sir when it out to be stopping you from harming yourself, like Java and C++ does.

Explanation of error: ‘NoneType’ object is not iterable

In python2, NoneType is the type of None. In Python3 NoneType is the class of None, for example:

>>> print(type(None))     #Python2
<type 'NoneType'>         #In Python2 the type of None is the 'NoneType' type.

>>> print(type(None))     #Python3
<class 'NoneType'>        #In Python3, the type of None is the 'NoneType' class.

Iterating over a variable that has value None fails:

for a in None:
    print("k")     #TypeError: 'NoneType' object is not iterable

Python methods return NoneType if they don’t return a value:

def foo():
    print("k")
a, b = foo()      #TypeError: 'NoneType' object is not iterable

You need to check your looping constructs for NoneType like this:

a = None 
print(a is None)              #prints True
print(a is not None)          #prints False
print(a == None)              #prints True
print(a != None)              #prints False
print(isinstance(a, object))  #prints True
print(isinstance(a, str))     #prints False

Guido says only use is to check for None because is is more robust to identity checking. Don’t use equality operations because those can spit bubble-up implementationitis of their own. Python’s Coding Style Guidelines — PEP-008

NoneTypes are Sneaky, and can sneak in from lambdas:

import sys
b = lambda x : sys.stdout.write("k") 
for a in b(10): 
    pass            #TypeError: 'NoneType' object is not iterable 

NoneType is not a valid keyword:

a = NoneType     #NameError: name 'NoneType' is not defined

Concatenation of None and a string:

bar = "something"
foo = None
print foo + bar    #TypeError: cannot concatenate 'str' and 'NoneType' objects

What’s going on here?

Python’s interpreter converted your code to pyc bytecode. The Python virtual machine processed the bytecode, it encountered a looping construct which said iterate over a variable containing None. The operation was performed by invoking the __iter__ method on the None.

None has no __iter__ method defined, so Python’s virtual machine tells you what it sees: that NoneType has no __iter__ method.

This is why Python’s duck-typing ideology is considered bad. The programmer does something completely reasonable with a variable and at runtime it gets contaminated by None, the python virtual machine attempts to soldier on, and pukes up a bunch of unrelated nonsense all over the carpet.

Java or C++ doesn’t have these problems because such a program wouldn’t be allowed to compile since you haven’t defined what to do when None occurs. Python gives the programmer lots of rope to hang himself by allowing you to do lots of things that should cannot be expected to work under exceptional circumstances. Python is a yes-man, saying yes-sir when it out to be stopping you from harming yourself, like Java and C++ does.

None and iterables are distinct types of objects in Python. None is the return value of a function that does not return anything, and we can use None to represent the absence of a value. An iterable is an object capable of returning elements one at a time, for example, a list. If you try to iterate over a None, you will raise the error “TypeError: ‘NoneType’ object is not iterable”.

This tutorial will go through the error in detail. We will go through an example scenario and learn how to solve the error.

TypeError: ‘NoneType’ object is not iterable

TypeError occurs in Python when you perform an illegal operation for a specific data type. The “‘NoneType’ object is not iterable” part of the error tells us that the TypeError is referring to the iteration operation. You cannot iterate over an object that is not iterable.

Another example of a non-iterable object is an integer.

An iterable is a Python object that you can use as a sequence. You can go to the next item in the sequence using the next() method.

d = {"two": 2, "four":4, "six": 6, "eight": 8, "ten": 10}

iterable = d.keys()

print(iterable)

dict_keys(['two', 'four', 'six', 'eight', 'ten'])

The output is the dictionary keys, which we can iterate over. We can loop over the items and get the values using a for loop:

for item in iterable:

    print(d[item])

Here we use item as the index for the key in the dictionary. The following result will print to the console:

2
4
6
8
10

We can also create an iterator to use the next() method

d = {"two": 2, "four":4, "six": 6, "eight": 8, "ten": 10} 

iterable = d.keys()

iterator = iter(iterable)

print(next(iterator))

print(next(iterator))

two

four

The code returns the first and second items in the dictionary.

For an object to be iterable, it must contain a value. A None value is not iterable because it represents a null value.

You will not raise this error when iterating over an empty list or an empty string. In Python, list and string are iterable data types.

Let’s look at examples of trying to iterate over a NoneType, which raises the error: “TypeError: ‘NoneType’ object is not iterable”.

Example: Function Does Not Return a Value

Let’s write a program that takes a list of sandwiches and filters out those that contain cheese in the name. The program will print the sandwiches to the console. First, we will define a function that filters out the sandwiches:

def select_sandwiches(sandwiches):
   
    selected_sandwiches = []
    
    for sandwich in sandwiches:
    
        if "cheese" in sandwich:
   
            selected_sandwiches.append(sandwich)

The function select_sandwiches() loops over the items in the sandwiches list. If the item contains the word cheese, we add it to the selected_sandwiches list.

Next, we will write a function that goes through the selected_sandwiches list and prints each value to the console.

def print_sandwiches(sandwich_names):

    for s in sandwich_names:
        
        print(s)

With the two functions in place, we can declare a list of sandwiches for our program to search through. We need to pass the list of sandwiches to our select_sandwiches() function:

sandwiches = ["cheese and ham", "chicken salad", "cheese and onion", "falafel", "cheese and pickle", "cucumber"]

sandwiches_with_cheese = select_sandwiches(sandwiches)

We can then print all of the sandwiches that contain the word cheese to the console using the print_sandwiches() function.

print_sandwiches(sandwiches_with_cheese)

Let’s run the code to see what happens:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
      1 print_sandwiches(sandwiches_with_cheese)

in print_sandwiches(sandwich_names)
      1 def print_sandwiches(sandwich_names):
      2     for s in sandwich_names:
      3         print(s)
      4 

TypeError: 'NoneType' object is not iterable

We get an error message because the function select_sandwiches() does not return a value to iterate over. Therefore when we call print_sandwiches(), the function tries to iterate over a None value.

Solution

To solve the error, we need to return a value in the select_sandwiches() function. Let’s look at the revised code:

def select_sandwiches(sandwiches):

    selected_sandwiches = []

    for sandwich in sandwiches:

        if "cheese" in sandwich:

            selected_sandwiches.append(sandwich)

    # Added a return statement

    return selected_sandwiches

def print_sandwiches(sandwich_names):

    for s in sandwich_names:

        print(s)

sandwiches = ["cheese and ham", "chicken salad", "cheese and onion", "falafel", "cheese and pickle", "cucumber"]

sandwiches_with_cheese = select_sandwiches(sandwiches)

print_sandwiches(sandwiches_with_cheese)

The select_sandwiches() function returns the selected_sandwiches list. Let’s run the code to see what happens:

cheese and ham
cheese and onion
cheese and pickle

The program selects and prints out the sandwiches that contain the word cheese.

How to Avoid the NoneType Exception

You can avoid the NoneType exception by checking if a value is equal to None before you try to iterate over that value. Let’s modify the print_sandwiches() function:

def select_sandwiches(sandwiches):

    selected_sandwiches = []

    for sandwich in sandwiches:

        if "cheese" in sandwich:

            selected_sandwiches.append(sandwich)

    # Added a return statement

    return selected_sandwiches

def print_sandwiches(sandwich_names):

    if sandwich_names is not None:

        for s in sandwich_names:

            print(s)
    else:

        print('You are trying to iterate over a NoneType')

sandwiches = ["cheese and ham", "chicken salad", "cheese and onion", "falafel", "cheese and pickle", "cucumber"]

sandwiches_with_cheese = select_sandwiches(sandwiches)

print_sandwiches(sandwiches_with_cheese)

Let’s run the code to see what happens:

cheese and ham
cheese and onion
cheese and pickle

The code executes successfully. However, by putting is not None into the print_sandwiches() function, we will not know if a function is missing a return statement. Therefore, if you encounter this error, you should accept it and resolve the issue instead of using is not None.

Summary

Congratulations on reading to the end of this tutorial. The error “TypeError: ‘NoneType’ object is not iterable” occurs when you try to iterate over a NoneType object. Objects like list, tuple, and string are iterables, but not None. To solve this error, ensure you assign any values you want to iterate over to an iterable object. A common mistake is not adding a return statement to a function, which will make the function return None instead of a value. To solve this, ensure the function returns an iterable value.

For further reading on TypeErrors involving NoneType objects go to the article: How to Solve Python TypeError: can only join an iterable.

Go to the online courses page on Python to learn more about Python for data science and machine learning.

Have fun and happy researching!

Explanation of error: ‘NoneType’ object is not iterable

In python2, NoneType is the type of None. In Python3 NoneType is the class of None, for example:

>>> print(type(None))     #Python2
<type 'NoneType'>         #In Python2 the type of None is the 'NoneType' type.

>>> print(type(None))     #Python3
<class 'NoneType'>        #In Python3, the type of None is the 'NoneType' class.

Iterating over a variable that has value None fails:

for a in None:
    print("k")     #TypeError: 'NoneType' object is not iterable

Python methods return NoneType if they don’t return a value:

def foo():
    print("k")
a, b = foo()      #TypeError: 'NoneType' object is not iterable

You need to check your looping constructs for NoneType like this:

a = None 
print(a is None)              #prints True
print(a is not None)          #prints False
print(a == None)              #prints True
print(a != None)              #prints False
print(isinstance(a, object))  #prints True
print(isinstance(a, str))     #prints False

Guido says only use is to check for None because is is more robust to identity checking. Don’t use equality operations because those can spit bubble-up implementationitis of their own. Python’s Coding Style Guidelines — PEP-008

NoneTypes are Sneaky, and can sneak in from lambdas:

import sys
b = lambda x : sys.stdout.write("k") 
for a in b(10): 
    pass            #TypeError: 'NoneType' object is not iterable 

NoneType is not a valid keyword:

a = NoneType     #NameError: name 'NoneType' is not defined

Concatenation of None and a string:

bar = "something"
foo = None
print foo + bar    #TypeError: cannot concatenate 'str' and 'NoneType' objects

What’s going on here?

Python’s interpreter converted your code to pyc bytecode. The Python virtual machine processed the bytecode, it encountered a looping construct which said iterate over a variable containing None. The operation was performed by invoking the __iter__ method on the None.

None has no __iter__ method defined, so Python’s virtual machine tells you what it sees: that NoneType has no __iter__ method.

This is why Python’s duck-typing ideology is considered bad. The programmer does something completely reasonable with a variable and at runtime it gets contaminated by None, the python virtual machine attempts to soldier on, and pukes up a bunch of unrelated nonsense all over the carpet.

Java or C++ doesn’t have these problems because such a program wouldn’t be allowed to compile since you haven’t defined what to do when None occurs. Python gives the programmer lots of rope to hang himself by allowing you to do lots of things that should cannot be expected to work under exceptional circumstances. Python is a yes-man, saying yes-sir when it out to be stopping you from harming yourself, like Java and C++ does.