List object is not callable в чем ошибка

Before you can fully understand what the error means and how to solve, it is important to understand what a built-in name is in Python.

What is a built-in name?

In Python, a built-in name is a name that the Python interpreter already has assigned a predefined value. The value can be either a function or class object. These names are always made available by default, no matter the scope. Some of the values assigned to these names represent fundamental types of the Python language, while others are simple useful.

As of the latest version of Python — 3.6.2 — there are currently 61 built-in names. A full list of the names and how they should be used, can be found in the documentation section Built-in Functions.

An important point to note however, is that Python will not stop you from re-assigning builtin names. Built-in names are not reserved, and Python allows them to be used as variable names as well.

Here is an example using the dict built-in:

>>> dict = {}
>>> dict
{}
>>>

As you can see, Python allowed us to assign the dict name, to reference a dictionary object.

What does «TypeError: ‘list’ object is not callable» mean?

To put it simply, the reason the error is occurring is because you re-assigned the builtin name list in the script:

list = [1, 2, 3, 4, 5]

When you did this, you overwrote the predefined value of the built-in name. This means you can no longer use the predefined value of list, which is a class object representing Python list.

Thus, when you tried to use the list class to create a new list from a range object:

myrange = list(range(1, 10))

Python raised an error. The reason the error says «‘list’ object is not callable», is because as said above, the name list was referring to a list object. So the above would be the equivalent of doing:

[1, 2, 3, 4, 5](range(1, 10))

Which of course makes no sense. You cannot call a list object.

How can I fix the error?

Suppose you have code such as the following:

list = [1, 2, 3, 4, 5]
myrange = list(range(1, 10))

for number in list:
    if number in myrange:
        print(number, 'is between 1 and 10')

Running the above code produces the following error:

Traceback (most recent call last):
  File "python", line 2, in <module>
TypeError: 'list' object is not callable

If you are getting a similar error such as the one above saying an «object is not callable», chances are you used a builtin name as a variable in your code. In this case and other cases the fix is as simple as renaming the offending variable. For example, to fix the above code, we could rename our list variable to ints:

ints = [1, 2, 3, 4, 5] # Rename "list" to "ints"
myrange = list(range(1, 10))

for number in ints: # Renamed "list" to "ints"
    if number in myrange:
        print(number, 'is between 1 and 10')

PEP8 — the official Python style guide — includes many recommendations on naming variables.

This is a very common error new and old Python users make. This is why it’s important to always avoid using built-in names as variables such as str, dict, list, range, etc.

Many linters and IDEs will warn you when you attempt to use a built-in name as a variable. If your frequently make this mistake, it may be worth your time to invest in one of these programs.

I didn’t rename a built-in name, but I’m still getting «TypeError: ‘list’ object is not callable». What gives?

Another common cause for the above error is attempting to index a list using parenthesis (()) rather than square brackets ([]). For example:

>>> lst = [1, 2]
>>> lst(0)

Traceback (most recent call last):
  File "<pyshell#32>", line 1, in <module>
    lst(0)
TypeError: 'list' object is not callable

For an explanation of the full problem and what can be done to fix it, see TypeError: ‘list’ object is not callable while trying to access a list.

✋ Update: This post was originally published on my blog decodingweb.dev, where you can read the latest version for a 💯 user experience. ~reza

The “TypeError: ‘list’ object is not callable” error occurs when you try to call a list (list object) as if it was a function!

Here’s what the error looks like:

Traceback (most recent call last):
  File "/dwd/sandbox/test.py", line 6, in 
    more_items = list(range(11, 20))
                 ^^^^^^^^^^^^^^^^^^^
TypeError: 'list' object is not callable

Calling a list object as if it’s a callable isn’t what you’d do on purpose, though. It usually happens due to a wrong syntax or overriding a function name with a list object.

Let’s explore the common causes and their solutions.

How to fix TypeError: ‘list’ object is not callable?

This TypeError happens under various scenarios:

1. Declaring a variable with a name that’s also the name of a function
2. Indexing a list by parenthesis rather than square brackets
3. Calling a method that’s also the name of a property
4. Calling a method decorated with @property

Declaring a variable with a name that’s also the name of a function: A Python function is an object like any other built-in object, such as str, int, float, dict, list, etc.

All built-in functions are defined in the builtins module and assigned a global name for easier access. For instance, list refers to the __builtins__.list function.

That said, overriding a function (accidentally or on purpose) with any value (e.g., a list object) is technically possible.

In the following example, we’ve declared a variable named list containing a list of numbers. In its following line, we try to create another list — this time by using the list() and range() functions:

list = [1, 2, 3, 4, 5, 6, 8, 9, 10] 
# ⚠️ list is no longer pointing to the list function

# Next, we try to generate a sequence to add to the current list
more_items = list(range(11, 20))
# 👆 ⛔ Raises: TypeError: ‘list’ object is not callable

If you run the above code, Python will complain with a «TypeError: ‘list’ object is not callable» error because we’ve already assigned the list name to the first list object.

We have two ways to fix the issue:

1. Rename the variable list
2. Explicitly access the list() function from the builtins module (__bultins__.list)

The second approach isn’t recommended unless you’re developing a module. For instance, if you want to implement an open() function that wraps the built-in open():

# Custom open() function using the built-in open() internally
def open(filename):
     # ...
     __builtins__.open(filename, 'w', opener=opener)
     # ...

In almost every other case, you should always avoid naming your variables as existing functions and methods. But if you’ve done so, renaming the variable would solve the issue.

So the above example could be fixed like this:

items = [1, 2, 3, 4, 5, 6, 8, 9, 10] 

# Next, we try to generate a sequence to add to the current list
more_items = list(range(11, 20))

This issue is common with function names you’re more likely to use as variable names. Functions such as vars, locals, list, all, or even user-defined functions.

In the following example, we declare a variable named all containing a list of items. At some point, we call all() to check if all the elements in the list (also named all) are True:

all = [1, 3, 4, True, 'hey there', 1]
# ⚠️ all is no longer pointing to the built-in function all()


# Checking if every element in all is True:
print(all(all))
# 👆 ⛔ Raises TypeError: 'list' object is not callable

Obviously, we get the TypeError because the built-in function all() is now shadowed by the new value of the all variable.

To fix the issue, we choose a different name for our variable:

items = [1, 3, 4, True, 'hey there', 1]


# Checking if every element in all is True:
print(all(items))
# Output: True

⚠️ Long story short, you should never use a function name (built-in or user-defined) for your variables!

Overriding functions (and calling them later on) is the most common cause of the «TypeError: ‘list’ object is not callable» error. It’s similar to calling integer numbers as if they’re callables.

Now, let’s get to the less common mistakes that lead to this error.

Indexing a list by parenthesis rather than square brackets: Another common mistake is when you index a list by () instead of []. Based on Python semantics, the interpreter will see any identifier followed by a () as a function call. And since the parenthesis follows a list object, it’s like you’re trying to call a list.

As a result, you’ll get the «TypeError: ‘list’ object is not callable» error.

items = [1, 2, 3, 4, 5, 6]

print(items(2))
# 👆 ⛔ Raises TypeError: 'list' object is not callable

This is how you’re supposed to access a list item:

items = [1, 2, 3, 4, 5, 6]

print(items[2])
# Output: 3

Calling a method that’s also the name of a property: When you define a property in a class constructor, it’ll shadow any other attribute of the same name.

class Book:
    def __init__(self, title, authors):
        self.title = title
        self.authors = authors

    def authors(self):
        return self.authors

book = Book('The Pragmatic Programmer', ['David Thomas', 'Andrew Hunt'])
print(book.authors())
# 👆 ⛔ Raises TypeError: 'list' object is not callable

In the above example, since we have a property named authors, the method authors() is shadowed. As a result, any reference to authors will return the property authors, returning a list object. And if you call this list object value like a function, you’ll get the «TypeError: ‘list’ object is not callable» error.

The name get_authors sounds like a safer and more readable alternative:

class Book:
    def __init__(self, title, authors):
        self.title = title
        self.authors = authors

    def get_authors(self):
        return self.authors

book = Book('The Pragmatic Programmer', ['David Thomas', 'Andrew Hunt'])
print(book.get_authors())
# Output: ['David Thomas', 'Andrew Hunt']

Calling a method decorated with @property decorator: The @property decorator turns a method into a “getter” for a read-only attribute of the same name. You need to access a getter method without parenthesis, otherwise you’ll get a TypeError.

class Book:
    def __init__(self, title, authors):
        self._title = title
        self._authors = authors

    @property
    def authors(self):
        """Get the authors' names"""
        return self._authors

book = Book('The Pragmatic Programmer', ['David Thomas', 'Andrew Hunt'])
print(book.authors())
# 👆 ⛔ Raises TypeError: 'list' object is not callable

To fix it, you need to access the getter method without the parentheses:

book = Book('The Pragmatic Programmer', ['David Thomas', 'Andrew Hunt'])
print(book.authors)
# Output: ['David Thomas', 'Andrew Hunt']

Problem solved!

Alright, I think it does it! I hope this quick guide helped you fix your problem.

Thanks for reading.

❤️ You might like:

• TypeError: ‘tuple’ object is not callable in Python
• TypeError: ‘dict’ object is not callable in Python
• TypeError: ‘str’ object is not callable in Python
• TypeError: ‘float’ object is not callable in Python
• TypeError: ‘int’ object is not callable in Python

The most common scenario where Python throws TypeError: ‘list’ object is not callable is when you have assigned a variable name as “list” or if you are trying to index the elements of the list using parenthesis instead of square brackets.

In this tutorial, we will learn what ‘list’ object is is not callable error means and how to resolve this TypeError in your program with examples.

There are two main scenarios where you get a ‘list’ object is not callable error in Python. Let us take a look at both scenarios with examples.

Scenario 1 – Using the built-in name list as a variable name

The most common mistake the developers tend to perform is declaring the Python built-in names or methods as variable names.

What is a built-in name?

In Python, a built-in name is nothing but the name that the Python interpreter already has assigned a predefined value. The value can be either a function or class object. 

The Python interpreter has 70+ functions and types built into it that are always available.

In Python, a list is a built-in function, and it is not recommended to use the built-in functions or keywords as variable names.

Python will not stop you from using the built-in names as variable names, but if you do so, it will lose its property of being a function and act as a standard variable.

Let us take a look at a simple example to demonstrate the same.

fruit = "Apple"
list = list(fruit)
print(list)

car="Ford"
car_list=list(car)
print(car_list)

Output

['A', 'p', 'p', 'l', 'e']
Traceback (most recent call last):
  File "c:PersonalIJSCodemain.py", line 6, in <module>
    car_list=list(car)
TypeError: 'list' object is not callable

If you look at the above example, we have declared a fruit variable, and we are converting that into a list and storing that in a new variable called “list“.

Since we have used the “list” as a variable name here, the list() method will lose its properties and functionality and act like a normal variable.

We then declare a new variable called “car“, and when we try to convert that into a list by creating a list, we get TypeError: ‘list’ object is not callable error message. 

The reason for TypeError is straightforward we have a list variable that is not a built function anymore as we re-assigned the built-in name list in the script. This means you can no longer use the predefined list value, which is a class object representing the Python list.

Solution for using the built-in name list as a variable name

If you are getting object is not callable error, that means you are simply using the built-in name as a variable in your code. 

fruit = "Apple"
fruit_list = list(fruit)
print(fruit_list)

car="Ford"
car_list=list(car)
print(car_list)

Output

['A', 'p', 'p', 'l', 'e']
['F', 'o', 'r', 'd']

In our above code, the fix is simple we need to rename the variable “list” to “fruit_list”, as shown below, which will fix the  ‘list’ object is not callable error. 

Scenario 2 – Indexing list using parenthesis()

Another common cause for this error is if you are attempting to index a list of elements using parenthesis() instead of square brackets []. The elements of a list are accessed using the square brackets with index number to get that particular element.

Let us take a look at a simple example to reproduce this scenario.

my_list = [1, 2, 3, 4, 5, 6]
first_element= my_list(0)
print(" The first element in the list is", first_element)

Output

Traceback (most recent call last):
  File "c:PersonalIJSCodetempCodeRunnerFile.py", line 2, in <module>
    first_element= my_list(0)
TypeError: 'list' object is not callable

In the above program, we have a “my_list” list of numbers, and we are accessing the first element by indexing the list using parenthesis first_element= my_list(0), which is wrong. The Python interpreter will raise TypeError: ‘list’ object is not callable error. 

Solution for Indexing list using parenthesis()

The correct way to index an element of the list is using square brackets. We can solve the ‘list’ object is not callable error by replacing the parenthesis () with square brackets [] to solve the error as shown below.

my_list = [1, 2, 3, 4, 5, 6]
first_element= my_list[0]
print(" The first element in the list is", first_element)

Output

 The first element in the list is 1

Conclusion

The TypeError: ‘list’ object is not callable error is raised in two scenarios 

1. If you try to access elements of the list using parenthesis instead of square brackets
2. If you try to use built-in names such as list as a variable name 

Most developers make this common mistake while indexing the elements of the list or using the built-in names as variable names. PEP8 – the official Python style guide – includes many recommendations on naming variables properly, which can help beginners.

Если вы работаете со списками в Python, вы могли столкнуться с ошибкой типа «Ошибка типа: объект «список» не может быть вызван в Python». Эта ошибка может быть весьма неприятной, особенно если вы не знаете, что она означает и как ее исправить. В этом сообщении блога мы подробно рассмотрим ошибку «TypeError: объект list» не может быть вызван в Python, что ее вызывает и как ее исправить.

Сообщение об ошибке «Ошибка типа: объект «список» не вызывается в Python» — это распространенное сообщение об ошибке, с которым вы можете столкнуться при работе со списками в Python. Эта ошибка возникает, когда вы пытаетесь использовать круглые скобки для вызова списка, но Python рассматривает это как вызов функции.

Например, предположим, что у вас есть список, содержащий некоторые значения:

my_list = [1, 2, 3, 4]

Если вы попытаетесь вызвать список как функцию следующим образом:

my_list()

Вы получите сообщение об ошибке, подобное этому:

TypeError: 'list' object is not callable

Это сообщение об ошибке сообщает вам, что вы пытаетесь вызвать список как функцию, что невозможно.

Что вызывает ошибку «TypeError: объект list» не может быть вызван в Python?

Ошибка «TypeError: объект list не вызывается в Python» возникает, когда вы пытаетесь использовать круглые скобки для вызова списка, но Python рассматривает это как вызов функции. Это может произойти по разным причинам, но наиболее распространенной причиной является конфликт имен.

Например, предположим, что у вас есть функция с именем my_list, которая принимает некоторые параметры и возвращает список:

def my_list(arg1, arg2):
    # Do something with the arguments
    return [arg1, arg2]

Теперь, если вы создадите список с тем же именем, что и функция:

my_list = [1, 2, 3, 4]

И попробуйте вызвать функцию:

my_list()

Вы получите ошибку «TypeError: объект list не может быть вызван в Python».

Другой распространенной причиной этой ошибки является забывание использовать оператор индекса ([]), который используется для доступа к элементам списка. Например, если у вас есть список:

my_list = [1, 2, 3, 4]

И вы пытаетесь получить доступ к элементу следующим образом:

my_list(0)

Вы получите ошибку «TypeError: объект list не может быть вызван в Python».

Как исправить ошибку «TypeError: объект list не может быть вызван в Python»

Существует несколько различных способов исправить ошибку «TypeError: объект list» не может быть вызван в Python, в зависимости от причины. Вот несколько различных подходов, которые вы можете использовать:

Подход 1: переименовать список

Если ошибка вызвана конфликтом имен, один из способов исправить ее — переименовать либо список, либо функцию. Например, вы можете переименовать список:

my_list = [1, 2, 3, 4]
result = my_list.pop()
print(result)

Это выведет:

4

Подход 2: использование оператора индекса

Если ошибка вызвана тем, что вы забыли использовать оператор индекса ([]), вы можете исправить это, используя правильный синтаксис для доступа к элементам списка. Например:

my_list = [1, 2, 3, 4]
result = my_list[0]
print(result)

Это выведет:

1

Подход 3: определение новой функции

Если ошибка вызвана перезаписью функции списком, вы можете определить новую функцию с другим именем. Например:

def my_function(arg1, arg2):
    return [arg1, arg2]

my_list = [1, 2, 3, 4]

def new_function(some_list):
    # Do something with the list
    pass

new_function(my_list)

Это приведет к вызову новой функции со списком в качестве аргумента без каких-либо ошибок.

Подход 4: исправление синтаксических ошибок

Если ошибка вызвана синтаксическими ошибками, вы можете исправить их, внимательно просмотрев свой код и убедившись, что используете правильный синтаксис. Например:

my_list = [1, 2, 3, 4]
if len(my_list) == 4:
    print('The list has four elements')
else:
    print('The list does not have four elements')

Это выведет:

The list has four elements

Заключение

Ошибка ‘TypeError: ‘list’ object is not callable in Python’ может быть весьма неприятной, особенно если вы не знаете, что ее вызывает и как ее исправить. Однако, поняв распространенные причины этой ошибки и различные подходы к ее устранению, вы сможете легко преодолеть эту ошибку и продолжить работу со списками в Python. Не забудьте внимательно просмотреть свой код, чтобы выявить и исправить любые синтаксические ошибки и всегда использовать правильный синтаксис при работе со списками.

Have you ever seen the TypeError object is not callable when running one of your Python programs? We will find out together why it occurs.

The TypeError object is not callable is raised by the Python interpreter when an object that is not callable gets called using parentheses. This can occur, for example, if by mistake you try to access elements of a list by using parentheses instead of square brackets.

I will show you some scenarios where this exception occurs and also what you have to do to fix this error.

Let’s find the error!

What Does Object is Not Callable Mean?

To understand what “object is not callable” means we first have understand what is a callable in Python.

As the word callable says, a callable object is an object that can be called. To verify if an object is callable you can use the callable() built-in function and pass an object to it. If this function returns True the object is callable, if it returns False the object is not callable.

callable(object)

Let’s test this function with few Python objects…

Lists are not callable

>>> numbers = [1, 2, 3]
>>> callable(numbers)
False

Tuples are not callable

>>> numbers = (1, 2, 3)
>>> callable(numbers)
False

Lambdas are callable

>>> callable(lambda x: x+1)
True

Functions are callable

>>> def calculate_sum(x, y):
...     return x+y
... 
>>> callable(calculate_sum)
True

A pattern is becoming obvious, functions are callable objects while data types are not. And this makes sense considering that we “call” functions in our code all the time.

What Does TypeError: ‘int’ object is not callable Mean?

In the same way we have done before, let’s verify if integers are callable by using the callable() built-in function.

>>> number = 10
>>> callable(number)
False

As expected integers are not callable 🙂

So, in what kind of scenario can this error occur with integers?

Create a class called Person. This class has a single integer attribute called age.

class Person:
    def __init__(self, age):
        self.age = age

Now, create an object of type Person:

john = Person(25)

Below you can see the only attribute of the object:

print(john.__dict__)
{'age': 25}

Let’s say we want to access the value of John’s age.

For some reason the class does not provide a getter so we try to access the age attribute.

>>> print(john.age())
Traceback (most recent call last):
  File "callable.py", line 6, in <module>
    print(john.age())
TypeError: 'int' object is not callable

The Python interpreter raises the TypeError exception object is not callable.

Can you see why?

That’s because we have tried to access the age attribute with parentheses.

The TypeError ‘int’ object is not callable occurs when in the code you try to access an integer by using parentheses. Parentheses can only be used with callable objects like functions.

What Does TypeError: ‘float’ object is not callable Mean?

The Python math library allows to retrieve the value of Pi by using the constant math.pi.

I want to write a simple if else statement that verifies if a number is smaller or bigger than Pi.

import math

number = float(input("Please insert a number: "))

if number < math.pi():
    print("The number is smaller than Pi")
else:
    print("The number is bigger than Pi")

Let’s execute the program:

Please insert a number: 4
Traceback (most recent call last):
  File "callable.py", line 12, in <module>
    if number < math.pi():
TypeError: 'float' object is not callable

Interesting, something in the if condition is causing the error ‘float’ object is not callable.

Why?!?

That’s because math.pi is a float and to access it we don’t need parentheses. Parentheses are only required for callable objects and float objects are not callable.

>>> callable(4.0)
False

The TypeError ‘float’ object is not callable is raised by the Python interpreter if you access a float number with parentheses. Parentheses can only be used with callable objects.

What is the Meaning of TypeError: ‘str’ object is not callable?

The Python sys module allows to get the version of your Python interpreter.

Let’s see how…

>>> import sys
>>> print(sys.version())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'str' object is not callable

No way, the object is not callable error again!

Why?

To understand why check the official Python documentation for sys.version.

That’s why!

We have added parentheses at the end of sys.version but this object is a string and a string is not callable.

>>> callable("Python")
False

The TypeError ‘str’ object is not callable occurs when you access a string by using parentheses. Parentheses are only applicable to callable objects like functions.

Error ‘list’ object is not callable when working with a List

Define the following list of cities:

>>> cities = ['Paris', 'Rome', 'Warsaw', 'New York']

Now access the first element in this list:

>>> print(cities(0))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'list' object is not callable

What happened?!?

By mistake I have used parentheses to access the first element of the list.

To access an element of a list the name of the list has to be followed by square brackets. Within square brackets you specify the index of the element to access.

So, the problem here is that instead of using square brackets I have used parentheses.

Let’s fix our code:

>>> print(cities[0])
Paris

Nice, it works fine now.

The TypeError ‘list’ object is not callable occurs when you access an item of a list by using parentheses. Parentheses are only applicable to callable objects like functions. To access elements in a list you have to use square brackets instead.

Error ‘list’ object is not callable with a List Comprehension

When working with list comprehensions you might have also seen the “object is not callable” error.

This is a potential scenario when this could happen.

I have created a list of lists variable called matrix and I want to double every number in the matrix.

>>> matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
>>> [[2*row(index) for index in range(len(row))] for row in matrix]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 1, in <listcomp>
  File "<stdin>", line 1, in <listcomp>
TypeError: 'list' object is not callable

This error is more difficult to spot when working with list comprehensions as opposed as when working with lists.

That’s because a list comprehension is written on a single line and includes multiple parentheses and square brackets.

If you look at the code closely you will notice that the issue is caused by the fact that in row(index) we are using parentheses instead of square brackets.

This is the correct code:

>>> [[2*row[index] for index in range(len(row))] for row in matrix]
[[2, 4, 6], [8, 10, 12], [14, 16, 18]]

Conclusion

Now that we went through few scenarios in which the error object is not callable can occur you should be able to fix it quickly if it occurs in your programs.

I hope this article has helped you save some time! 🙂