Not supported between instances of str and int как исправить

In Python, we can only compare objects using mathematical operators if they are the same numerical data type. Suppose you use a comparison operator like the greater than the operator or >, between a string and an integer. In that case, you will raise the TypeError: ‘>’ not supported between instances of ‘str’ and ‘int’. This article will go through the error in detail, an example, and how to solve it.

TypeError: ‘>’ not supported between instances of ‘str’ and ‘int’

Python is a statically typed programming language, which means you have to change the type of a value before comparing it to a value of a different type. In the case of a string and an integer, you have to convert the string to an integer before using mathematical operators. This particular TypeError is not limited to the “greater than” comparison and can happen with any comparison operator, for example, less than (<), less than or equal to (<=) or greater than or equal to (>=).

Example: Using the input() Function to Compare Numbers

You will typically encounter this error when using the input() function because it will return a string. Let’s look at an example of a program that takes an input and then tries to find the most significant number out of a collection of numbers, including the input.

# Input number

number = input("Enter a number to compare:  ")

# Print output

print(f'The maximum number is {max(2, 4, 5)}')

print(f'The maximum number is {max(2, number, 5)}')

Enter a number to compare:  20    

The maximum number is 5

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
print(f'The maximum number is {max(2, number, 5)}')

TypeError: '>' not supported between instances of 'str' and 'int'

In the first part of the code, we pass three integers to the max function, which will find the maximum number, 5. However, in the second part of the code, we give a string to the max function with two other integers, we raise the TypeError:’>’ not supported between instances of ‘str’ and ‘int’. The error occurs when we compare two values whose data types are different, a string and an integer.

Generally, we raise a TypeError whenever we try to do an illegal operation for a particular object type. Another typical example is TypeError: ‘int’ object is not subscriptable, which occurs when accessing an integer like a list.

Solution

Instead of passing a string to the max function, we can wrap the input() function in the int() function to convert the value to an integer. The process is of converting a literal of one type is called type casting or explicit type conversion. We can use Python inbuilt functions like int(), float() and str() for typecasting.

# Input number 

number = int(input("Enter a number to compare:  "))

# Print output
 
print(f'The maximum number is {max(2, 4, 5)}')

print(f'The maximum number is {max(2, number, 5)}')

Enter a number to compare:  20

The maximum number is 5

The maximum number is 20

Our code now works successfully. The int() converts the string input to an integer to compare the two other integers.

Summary

Congratulations on making it to the end of this tutorial. To summarize, we raise the TypeError: ‘>’ not supported between instance of ‘str’ and ‘int’ when trying to use the greater than comparison operator between a string and an integer. This TypeError generalizes all comparison operators, not just the > operator.

To solve this error, convert any string values to integers using the int() function before comparing them with integers.

To learn more about Python, specific to data science and machine learning, go to the online courses page for Python.

Have fun and happy researching!

With the “TypeError: ‘<‘ not supported between instances of ‘str’ and ‘int’” error you are getting, you can use the int() method to fix it. Follow this article for details on how to fix it.

Only objects with the same numerical data type can be compared in Python using mathematical operators. If you employ a comparison operator, such as the more significant than the operator or >, you will cause this error.

Example:

You will get this problem because a string can’t compare to an integer. Look at the example below and determine if the input number is smaller than 18.

Code:

# Input age
age = input("Enter your age: ")

if age < 18:
	print("You must be over 18 to enter")
else:
	print("Welcome to our website")

Input:

Enter your age: 17

Output:

Traceback (most recent call last):
  File "main.py", line 4, in <module>
    if age < 18:
TypeError: '<' not supported between instances of 'str' and 'int'

As you can see, we can’t compare “age” with 18. The output will show you the error message: “TypeError:'<‘ not supported between instances of ‘str’ and ‘int’” because the input() method returns a string. This means our code tries to compare a string (the value in “age”) to an integer.

Solutions to fix this error

We should change the type of the input by function int(). After we wrap the string with int() method, the “age” type becomes an integer so we can compare it with another integer belike 18. You can use some Python functions like str() and float() to get the familiar result.

Code:

# Input age
age = int(input("Enter your age: "))

if age < 18:
 	print("You must be over 18 to enter")
else:
  	print("Welcome to our website")

Input:

Enter your age: 17

Output:

You must be over 18 to enter

So we can compare age with 18 now after we wrap the input() inside the int().

Summary

To summarize, the error TypeError:'<‘ not supported between the instance of ‘str’ and ‘int’ will occurs when you use any comparison operator to compare a string to an integer. The best way to solve this problem is to convert the string values into the same type value by built-in functions like float(), int().

Maybe you are interested in similar errors:

• TypeError: ‘module’ object is not callable in python
• TypeError: ‘nonetype’ object is not callable
• TypeError: ‘NoneType’ object is not iterable in Python
• TypeError: ‘set’ object is not subscriptable in Python
• TypeError: ‘str’ object does not support item assignment
• TypeError: ‘<‘ not supported between instances of ‘NoneType’ and ‘int’

You can only compare items using mathematical operators if they have the same numerical data type. If you try to compare a string and an integer, you’ll encounter an error that says “not supported between instances of ‘str’ and ‘int’”.

In this guide, we discuss what this error means and why it is raised. We walk through an example scenario where this error is present so we can talk about how to fix it.

typeerror: ‘>’ not supported between instances of ‘str’ and ‘int’

Strings and integers cannot be compared using comparison operators. This is because strings and integers are different data types.

Python is a statically typed programming language. You have to manually change the type of a data if you need to compare it with a value of another type.

For instance, suppose you want to convert a string to an integer. You have to manually convert the string to an integer before the comparison will work.

The “typeerror: ‘>’ not supported between instances of ‘str’ and ‘int’” error occurs when you try to perform a “greater than” comparison on a string and an integer.

This error can happen with any comparison operation, such as a less than (<), less than or equal to (<=), or greater than or equal to (>=).

An Example Scenario

We build a program that calculates the letter grade a student has earned in a test.

To start, ask a user to insert a numerical grade which we will later convert to a letter grade using an input() statement:

numerical_grade = input("What grade did the student earn? ")

Then, use an “if” statement to calculate the student’s numerical grade:

if numerical_grade > 80:
	letter = "A"
elif numerical_grade > 70:
	letter = "B"
elif numerical_grade > 60:
	letter = "C"
elif numerical_grade > 50:
	letter = "D"
else:
	letter = "F"
print(letter)

This code compares numerical_grade to a series of values. First, our code checks if numerical_grade is greater than 80. If it is, the value of “letter” becomes “A”. Otherwise, our code checks the next “elif” statement.

If the “if” and “elif” statements all evaluate to False, our code sets the value of “letter” to “F”.

At the end of our program, we print the letter grade a student has earned to the console.

Run our code and see what happens:

What grade did the student earn? 64
Traceback (most recent call last):
  File "main.py", line 3, in <module>
	if numerical_grade > 80:
TypeError: '>' not supported between instances of 'str' and 'int'

Our code does not run successfully. Our code asks us to insert a student grade. When our code goes to make its first comparison, an error is returned.

The Solution

The input() method returns a string. This means our code tries to compare a string (the value in “numerical_grade”) to an integer.

We solve this problem by converting “numerical_grade” to an integer before we perform any comparisons in our code:

numerical_grade = int(input("What grade did the student earn? "))

The int() method converts the value the user inserts into our program to an integer.

Try to run our code again:

What grade did the student earn? 64
C

Our code works successfully. This is because we now compare two integer values instead of an integer and a string.

Conclusion

The “typeerror: ‘>’ not supported between instances of ‘str’ and ‘int’” error is raised when you try to compare a string to an integer.

To solve this error, convert any string values to integers before you attempt to compare them to an integer. Now you’re ready to solve this common Python error in your code like a professional software developer.