Object of type io textiowrapper has no len ошибка

The complete code is as follows:

from Crypto.Protocol.KDF import scrypt
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes

class transmitter():

    def __init__(self):

        self.random_password = None
        self.message_plain = True
        self.key = None
        self.salt = None

        self.password_option()
        self.text_option()
        self.encrypt()


    def password_option(self):

        while ( self.random_password == None ):

            random = input("nDo you want to generate a random symmetric key? (y/n)nn>>> ").strip().lower()

            if random == "y":
                self.random_password = True
                self.random()

            elif random == "n":
                self.random_password = False
                self.random()

            else:
                pass

    def text_option(self):

        if self.message_plain:

            question = input("nHow will you enter your message?nn[1] filenn[2] directly in the programnn>>> ").strip()

            if question == "1":
                path = input("nEnter the file pathnn>>> ")
                name = path.split("\")[-1]
                with open(name,mode = "r") as self.message_plain:
                    self.message_plain.read().encode("utf-8")

            elif question == "2":
                self.message_plain = input("nEnter your messagenn>>> ").strip()
                self.message_plain = self.message_plain.encode("utf-8")


    def random(self):

        if self.random_password:
            password = "password".encode("utf-8")
            self.salt = get_random_bytes(16)
            self.key = scrypt(password, self.salt, 16, N=2**14, r=8, p=1)

        else:
            password = input("nEnter your passwordnn>>> ").strip()
            self.salt = get_random_bytes(16)
            self.key = scrypt(password.encode("utf-8"), self.salt, 16, N=2**14, r=8, p=1)


    def encrypt(self):

        cipher = AES.new(self.key,AES.MODE_GCM)
        cipher.update(b"header")
        cipher_text,tag_mac = cipher.encrypt_and_digest(self.message_plain)
        transmitted_message = cipher_text,tag_mac,self.salt,cipher.nonce
        Receptor(transmitted_message)

class receiver():

    def __init__(self,received_message):
        # nonce = aes_cipher.nonce
        self.cipher_text,self.tag_mac,self.salt,self.nonce = received_message
        self.decrypt(self.cipher_text,self.tag_mac,self.salt,self.nonce)

    def decrypt(self,cipher_text,tag_mac,salt,nonce):

        try:
            password = input("nEnter your passwordnn>>> ").strip()
            decryption_key = scrypt(password.encode("utf-8"), salt, 16, N=2**14, r=8, p=1)
            cipher = AES.new(decryption_key,AES.MODE_GCM,nonce)
            cipher.update(b"header")
            plain_text = cipher.decrypt_and_verify(cipher_text,tag_mac)
            plain_text = plain_text.decode("utf-8")
            print(f"nText -> {plain_text}n")

        except ValueError:
            print("nAn error has occurred..n")

if __name__ == '__main__':
    init = transmitter()

And the error is as follows:

Traceback (most recent call last):
  File ".crypto.py", line 109, in <module>
    init = Emisor()
  File ".crypto.py", line 16, in __init__
    self.encrypt()
  File ".crypto.py", line 74, in encrypt
    cipher_text,tag_mac = cipher.encrypt_and_digest(self.message_plain)
  File "C:UsersEQUIPOAppDataLocalProgramsPythonPython37-32libsite-packagesCryptoCipher_mode_gcm.py", line 547, in encryp
t_and_digest
    return self.encrypt(plaintext, output=output), self.digest()
  File "C:UsersEQUIPOAppDataLocalProgramsPythonPython37-32libsite-packagesCryptoCipher_mode_gcm.py", line 374, in encryp
t
    ciphertext = self._cipher.encrypt(plaintext, output=output)
  File "C:UsersEQUIPOAppDataLocalProgramsPythonPython37-32libsite-packagesCryptoCipher_mode_ctr.py", line 189, in encryp
t
    ciphertext = create_string_buffer(len(plaintext))
TypeError: object of type '_io.TextIOWrapper' has no len()

I have tried everything but honestly, I don’t know what else to do.
Does anyone know what could be wrong?

Basically, what I want to do is save the result of reading a certain file in a variable. So that I can encrypt it. Fortunately, the rest of the code is doing well, only that one block of code (the first one I put in the question) that presents the error.

The python error TypeError: object of type ‘type’ has no len() occurs while attempting to find the length of an object that returns ‘type’. The python variables can store object data types. If a python variable refers a data type, it can’t be used in length function. The Length function is used for data structures that store multiple objects. The data type of the variable that store another data type is called ‘type’.

For example list is a data type, list() returns a object of type list. int is a data type, where as int() returns int value. Python supports to store a data type and value in a variable.

a = int   -- stores data type
a = int() -- stores a int value

The python variables can store the data types and classes. These variables are not assigned any value, or objects. The length function can not be called the variables which are not allocated with any value or object. If you call the length function for these variables of ‘type’, it will throw the error TypeError: object of type ‘type’ has no len()

The basic data types are int, float, long, bool, complex etc. Some of the collections types are list, tuple, set, dict etc. Python allows to store these data types in a variable. The data type of the variable that store another data type is called ‘type’.

Exception

The error TypeError: object of type ‘type’ has no len() will show the stack trace as below

Traceback (most recent call last):
  File "/Users/python/Desktop/test.py", line 2, in <module>
    print len(s)
TypeError: object of type 'type' has no len()
[Finished in 0.1s with exit code 1]

How to reproduce this issue

If a python variable is assigned with a data type, the type of the variable would have ‘type’. If the length function is invoked for the ‘type’ variable, the error TypeError: object of type ‘type’ has no len() will be thrown.

s=list
print len(s)

Output

Traceback (most recent call last):
  File "/Users/python/Desktop/test.py", line 2, in <module>
    print len(s)
TypeError: object of type 'type' has no len()
[Finished in 0.1s with exit code 1]

Root Cause

The python variables are used to store any object or value. The values of the primitive data type such as int, float, long, boot etc can be stored in any python variable. Python is an object oriented programming language. The objects can be stored in Python variables. As the python variables are not declared with any data types, python can support to store a python function and a data type.

If a data type (not a value or object) is stored with a python variable, the length function can not be used for such variable. So, the error TypeError: object of type ‘type’ has no len() is thrown

Solution 1

The python variable which is assigned with a data type, should be assigned with a value or object. If the variable is not assigned with any value or object , assign with an object such as list, tuple, set, dictionary etc.

list – is a data type, where as list() is an object of type list

s=list()
print len(s)

Output

0
[Finished in 0.1s]

Solution 2

Due to the dynamic creation of the variable the python variable may not assigned with data types. The datatype of the variable is ‘type’. In this case, the data type must be checked before the length function is called.

s=list
print type(s)
if s is list : 
	print "Value is type"
else:
	print (len(s))

Output

<type 'type'>
Value is type
[Finished in 0.0s]

Solution 3

The python variable should be validated for the data type. The length function is used to find the number of items in the objects. Before calling the length function, the object must be validated for the collection of items.

s=list
print type(s)
if type(s) in (list,tuple,dict, str): 
	print (len(s))
else:
	print "not a list"

Output

<type 'type'>
not a list
[Finished in 0.1s]

Solution 4

The try and except block is used to capture the unusual run time errors. If the python variable contains expected value, then it will execute in the try block. If the python variable contains the unexpected value, then the except block will handle the error.

s=type
print s
try :
	print (len(s))
except :
	print "Not a list"

Output

<type 'type'>
Not a list
[Finished in 0.0s]

 Traceback (most recent call last):
  File "C:/Users/Администратор/PycharmProjects/Task/parser.py", line 130, in <module>
    call_all_func(resources)
  File "C:/Users/Администратор/PycharmProjects/Task/parser.py", line 112, in call_all_func
    item_title = get_item_title(item_page,title_rule)
  File "C:/Users/Администратор/PycharmProjects/Task/parser.py", line 35, in get_item_title
    soup = BeautifulSoup(item_page, 'lxml')
  File "C:UsersАдминистраторAppDataLocalProgramsPythonPython37-32libsite-packagesbs4__init__.py", line 267, in __init__
    elif len(markup) <= 256 and (
TypeError: object of type 'NoneType' has no len()
Process finished with exit code 1

Как я понял из ошибки,ошибка содержится в этом участке кода:

 # < Собираем заголовки с страницы.
def get_item_title(item_page,title_rule):
    soup = BeautifulSoup(item_page, 'lxml')
    item_title = soup.find(title_rule[0],{title_rule[1]:title_rule[2]})
    print(item_title)
    return item_title['content']

В title_rule=meta , title_rule=property , title_rule=og:title

Я решил сделать print(item_title) На выводе:

 vesti
кол-во ссылок: 34
http://vesti.kz//khl/269571/
<meta content='Прямая трансляция первого матча "Барыса" в новом сезоне КХЛ' property="og:title"/>
http://vesti.kz//profi/269572/
<meta content='"Я вернусь в Украину чемпионом мира". Деревянченко сделал очередное заявление перед боем с Головкиным' property="og:title"/>
http://vesti.kz//mirfutbol/269569/
<meta content="Криштиану Роналду составил завещание" property="og:title"/>
http://vesti.kz//wta/269568/
<meta content="Путинцева показала лучший результат в карьере и завершила выступление на US Open " property="og:title"/>
http://vesti.kz//mirfutbol/269566/
<meta content="Месси получил приз фонда Папы Римского " property="og:title"/>
http://vesti.kz//amateur/269565/
<meta content="Казахстанский боксер рассказал о подготовке к ЧМ и включил Узбекистан в число главных соперников" property="og:title"/>
http://vesti.kz//national/269564/
<meta content="Сборная Казахстана начала подготовку к матчам с Кипром и Россией в отборе на Евро-2020" property="og:title"/>
http://vesti.kz//sportsout/269563/
<meta content="Китайский миллиардер из рейтинга Forbes передал Головкину эстафету в челлендже" property="og:title"/>
http://vesti.kz//uefa/269509/
<meta content='Кто из звезд "Манчестер Юнайтед" может приехать в Казахстан на матч с "Астаной" в Лиге Европы' property="og:title"/>
http://vesti.kz//france/269562/
<meta content="ПСЖ подписал трехкратного победителя Лиги чемпионов и отдал в аренду чемпиона мира" property="og:title"/>
http://vesti.kz//amateur/269561/
<meta content="Василий Левит оценил свою форму и озвучил задачу на ЧМ-2019 по боксу " property="og:title"/>
http://vesti.kz//mirfutbol/269560/
<meta content="ФИФА назвала трех претендентов на награду лучшему футболисту года" property="og:title"/>
http://vesti.kz//profi/269547/
Traceback (most recent call last):
  File "C:/Users/Администратор/PycharmProjects/Task/parser.py", line 130, in <module>
    call_all_func(resources)
  File "C:/Users/Администратор/PycharmProjects/Task/parser.py", line 112, in call_all_func
    item_title = get_item_title(item_page,title_rule)
  File "C:/Users/Администратор/PycharmProjects/Task/parser.py", line 35, in get_item_title
    soup = BeautifulSoup(item_page, 'lxml')
  File "C:UsersАдминистраторAppDataLocalProgramsPythonPython37-32libsite-packagesbs4__init__.py", line 267, in __init__
    elif len(markup) <= 256 and (
TypeError: object of type 'NoneType' has no len()
Process finished with exit code 1

После вывода (если я правильно понял) код ругается на эту ссылку.

Как решить эту ошибку? По ошибке мне понятно только

что объект типа ‘NoneType’ не имеет len ()

Отредактировано r4khic (Сен. 3, 2019 08:16:03)