Object of type int has no len python ошибка

It sounds like you have a mixed list of integers and strings and want to sort by length of the strings. If that is the case, convert the entire list to like types — strings — before sorting.

Given:

>>> li=[1,999,'a','bbbb',0,-3]

You can do:

>>> sorted(map(str, li), key=len)   
['1', 'a', '0', '-3', '999', 'bbbb']

If you want a two key sort by length then ascibetible, you can do:

>>> sorted(map(str, li), key=lambda e: (len(e), e))
['0', '1', 'a', '-3', '999', 'bbbb']

You can sort without changing the object type by adding str to the key function:

>>> sorted(li, key=lambda e: (len(str(e)), str(e)))
[0, 1, 'a', -3, 999, 'bbbb']

This error occurs when you pass an integer to a len() function call. Integers are whole numbers without decimals. In Python, numerical values do not have a length.

You can solve the error by only passing iterable objects to the len() function. For example, you can pass an integer to a range() function call to get a range object, which is iterable and has a length. For example,

my_int = 5

rng = range(my_int)

print(len(rng))

This tutorial will go through the error and how to solve it with code examples.

TypeError: object of type ‘int’ has no len()

We raise a Python TypeError when attempting to perform an illegal operation for a specific type. In this case, the type is int.

The part ‘has no len()‘ tells us the map object does not have a length, and therefore len() is an illegal operation for the int object.

Retrieving the length of an object is only suitable for iterable objects, like a list or a tuple.

An integer is a whole number, that can be positive or negative, without decimals and of unlimited length.

The len() method implicitly calls the dunder method __len__() which returns a positive integer representing the length of the object on which it is called. All iterable objects have __len__ as an attribute. Let’s check if __len__ is in the list of attributes for an int object and a list object using the built-in dir() method.

my_int = 4

print(type(my_int))

print('__len__' in dir(my_int))

<class 'int'>
False

We can see that __len__ is not present in the attributes of the int object.

lst = ["Einstein", "Feynman", "Dirac"]

print(type(lst))

print('__len__' in dir(lst))

<class 'list'>
True

We can see that __len__ is present in the attributes of the list object.

Example

Let’s look at an example of trying to get the length of an int object. First, we will define a function that counts the number of cakes in a list of baked goods provided by a bakery.

def get_total_cakes(bakery_list):

    cake_count = sum(map(lambda x: "cake" in x, bakery_list))

    print(f'Number of cakes in shop: {len(cake_count)}')

Next, we will define the list of baked goods to pass to the function call.

baked_goods = ['chocolate cake', 'baklava', 'genoise cake', 'chiffon cake', 'brownie', 'strawberry crumble', 'angel food cake']

Next, we will call the get_total_cakes() function to get the number of cakes in the list:

get_total_cakes(baked_goods)

Let’s run the code to see what happens:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Input In [15], in <cell line: 3>()
      1 baked_goods = ['chocolate cake', 'baklava', 'genoise cake', 'chiffon cake', 'brownie', 'strawberry crumble', 'angel food cake']
----> 3 get_total_cakes(baked_goods)

Input In [14], in get_total_cakes(bakery_list)
      1 def get_total_cakes(bakery_list):
      2     cake_count = sum(map(lambda x: "cake" in x, bakery_list))
----> 3     print(f'Number of cakes in shop: {len(cake_count)}')

TypeError: object of type 'int' has no len()

The error occurs because the cake_count variable is an integer. The combination of sum() and map() counts the elements in a list by a specified condition and returns an integer. Therefore, when we try to get the length of cake_count using len(), we are trying to get the length of an integer.

We can check the type of an object by using the built-in type() function:

baked_goods = ['chocolate cake', 'baklava', 'genoise cake', 'chiffon cake', 'brownie', 'strawberry crumble', 'angel food cake']

cake_count = sum(map(lambda x: "cake" in x, baked_goods))

print(type(cake_count))

<class 'int'>

Solution

We can solve this error by removing the len() function call in the print statement. Let’s look at the revised code:

def get_total_cakes(bakery_list):
    cake_count = sum(map(lambda x: "cake" in x, bakery_list))
    print(f'Number of cakes in shop: {cake_count}')

Let’s define the list of baked goods and pass the list to the get_total_cakes() function call.

baked_goods = ['chocolate cake', 'baklava', 'genoise cake', 'chiffon cake', 'brownie', 'strawberry crumble', 'angel food cake']

get_total_cakes(baked_goods)

Let’s run the code to get the number of cakes.

Number of cakes in shop: 4

Summary

Congratulations on reading to the end of this tutorial!

For further reading on the has no len() TypeErrors, go to the article:

• How to Solve Python TypeError: object of type ‘builtin_function_or_method’ has no len()
• How to Solve Python TypeError: object of type ‘filter’ has no len()
• How to Solve Python TypeError: object of type ‘float’ has no len()

To learn more about Python for data science and machine learning, go to the online courses page on Python, which provides the best, easy-to-use online courses.

In python, the error “TypeError: object of type ‘int’ has no len()” occurs when the length function is invoked on objects that does not support the length function. The length function is supported by iterable objects such as list, tuple, dictionary and string.

The length function is used to find the length of the string or the number of objects in a structured objects such as list, tuple and dictionary. The length function does not supported by the data types such as int, float, long, boolean, complex data types. If the length function is invoked on unsupported objects, the python interpreter will cause the error.

The purpose of the len() function is to determine the length of the list, tuple, dictation, or string. In this article, we can see what this error is, how this error can be resolved. The error would be thrown as like below.

Traceback (most recent call last):
  File "/Users/python/Desktop/test.py", line 2, in <module>
    print (len(s))
TypeError: object of type 'int' has no len()
[Finished in 0.2s with exit code 1]

Different Variation of the error

In different contexts the “TypeError: object of type ‘int’ has no len()” error is thrown in various forms in python. The numerous variations of TypeError are shown below.

TypeError: object of type 'NoneType' has no len()
TypeError: object of type 'int' has no len()
TypeError: object of type 'float' has no len()
TypeError: object of type 'long' has no len()
TypeError: object of type 'bool' has no len()
TypeError: object of type 'complex' has no len()
TypeError: object of type 'type' has no len()
TypeError: object of type 'builtin_function_or_method' has no len()

Root Cause

The root cause of this error is that the len() function is invoked on objects that are not supported to calculate the length. Iterable objects such as list, tuple, dictionary, and strings are supported to find the length of the elements in it.

The len() function does not make sense for types such as integer, float, boolean, long, complex. The Python interpreter will throw this error when the len() function is invoked on this.

How to reproduce this error

If the len() function is invoked for the unsupported objects such as int, float, boolean, long etc, this error will be thrown. calling the len() function for the unsupported objects to reproduce this error “TypeError: object of type ‘int’ has no len()” in python.

s=5
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 'int' has no len()
[Finished in 0.2s with exit code 1]

Solution 1

The len() function should only be used for iterable objects such as list, tuple, dictionary and string. Make sure you return any of the objects. Changing the primary data types to the iterable objects will resolve this error “TypeError: object of type ‘int’ has no len()” in python.

s = [5,4]
print (len(s))

Output

2

Solution 2

The len() function must be called before checking the object type. If the object is an iterable object, such as a list, tuple, dictionary, or string, the len() function will be called. Otherwise the error message “TypeError: object of type ‘int’ has no len()” will be shown to the user that the length of the object can not be found.

s=[2]
print type(s)
if type(s) in (list,tuple,dict, str): 
	print (len(s))
else:
	print "not a list"

Output

1

Solution 3

The length can not be determined if the argument for the len() function is None. The value of the argument must be checked for non-None before calling the len() function. The error message “TypeError: object of type ‘NoneType’ has no len()” will be shown as in the example below.

s=None
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 'NoneType' has no len()
[Finished in 0.1s with exit code 1]

Solution

s=None
print type(s)
if s is None : 
	print "a None value"
else:
	print (len(s))

Output

a None value

Solution 4

The length can not be determined if the argument for the len() function is a python type. The value of the argument must be checked for type before calling the len() function or default value is set. The error message “TypeError: object of type ‘type’ has no len()” will be shown as in the example below.

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 0.0s with exit code 1]

Solution

s=list()
print len(s)

Output

0

Solution 5

The length can not be determined if the argument for the len() function is a python build in function. The value of the argument must be checked before calling the len() function. The error message will be shown as in the example below.

s=len
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 'builtin_function_or_method' has no len()
[Finished in 0.1s with exit code 1]

Solution

s=(2,3)
print len(s)

Output

2

In this article, we will learn about the TypeError: object of type ‘int’ has no len.

What is TypeError: object of type ‘int’ has no len?

This error is generated when we try to calculate the length of an integer value. But integer don’t have any length. Thus the error is raised.

Let us understand it more with the help of an example.

Example

# Importing random module
import random 

# Using randit function of random module
var = random.randint(0, 20)

# Printing Random value
print("Random value: ",var)

# Printing length of variable
print("Length of variable: ",len(var))

Output

Random value:  18
  File "len.py", line 12, in <module>
    print("Length of variable: ",len(var))
TypeError: object of type 'int' has no len()

Explanation

In the above example, we imported the random module of python. There are various function available in random module of python. In this particular code, we used the randint() function. This function returns any random integer within the specified parameter value.

After generating the random integer we stored it in the variable ‘var’. And printed it in the next line. There’s no error encountered until now. But when we try to try to calculate the length of the variable ‘var’ in line-12 of the code. An error is encountered. This TypeError is raised because we were trying to calculate the length of an integer. And we know integers don’t have any length.

Solution

# Importing random module
import random 

# Using randit(start,end) function of random module
var = random.randint(0, 20)

# Printing Random value
print("Random value: ",var)

# Printing length of variable
print("Length of variable: ",len(str(var))) 

Output

Random value:  2
Length of variable:  1

Explanation

As discussed earlier we can not calculate the length of an integer. But we can calculate the length of the string. So what we can do is, change the integer value to the string. And then calculate the length of that string.

Here we used a built-in function str() to change ‘var’ to string.

Conclusion

This TypeError is raised when we try to calculate the length of an integer using len(). To work around this error we can convert the integer value to string. And then calculate the length of the string.