How to Fix: TypeError: ‘str’ object is not callable in Python

TypeError: ‘str’ object This is one of the most common—and most confusing—errors for new Python developers. You see it, and you think, “What’s a ‘callable’?” The error TypeError: ‘str’ object is not callable suggests an attempt to call a string as if it were a function.

Let’s break it down in plain English, examining what a TypeError: ‘str’ object is not callable really means, especially when encountering this ‘str’ object issue.

What Does This Error Mean?

• TypeError: The operation you tried is not valid for this type of data.
• 'str' object: The data you’re using is a string (text).
• is not callable: You are trying to use it like a function, but it’s not a function, hence the error TypeError: ‘str’ object is not callable.

A “callable” is anything in Python you can call using parentheses (). Functions are callable, but encountering a TypeError: ‘str’ object indicates misuse.

print("Hello")  # print is callable
len([1, 2, 3])  # len is callable

A simple string variable is not.

my_name = "Alice"
my_name()  # This crashes! "Alice" is not a function.

This error means you are trying to use parentheses () on a variable that is just a string.

There are two main reasons this happens, leading to the common TypeError: ‘str’ object is not callable.

Cause 1 (Most Common): You Overwrote a Built-in Function

This is the #1 mistake. You accidentally used a built-in Python function name as a variable name, which often results in a TypeError: ‘str’ object is not callable. This mistake of using a string like a function commonly triggers the TypeError.

Problem Code:

# You create a variable named 'str'
str = "I am a string"

# ... later in your code ...
# You try to use the *real* str() function to convert a number
my_number = 123
my_string = str(my_number)  # This is where it breaks!

# TypeError: 'str' object is not callable

Why it fails: Python thinks you are trying to call your "I am a string" variable like a function. It’s confused.

The Fix: NEVER use built-in function names as your variable names. Rename your variable to something else, like my_string.

Correct Code:

# Use a different variable name
my_string = "I am a string"

# Now, the 'str()' function is safe and works!
my_number = 123
my_string_version = str(my_number)

print(my_string_version)

Common built-in names to AVOID:

• str
• list
• dict
• set
• sum
• len
• min
• max

Cause 2: You Forgot a Math Operator

This often happens when you’re writing a formula and forget a * for multiplication, leading to the infamous TypeError: ‘str’ object. Ensure you avoid a TypeError: ‘str’ object is not callable by correctly using operators in expressions to prevent accidental function-like treatment of strings.

Problem Code:

x = 10
y = 5

# Python thinks 10(5 + 2) means "call the function 10"
result = x(y + 2) 

# TypeError: 'int' object is not callable
# (This is the same error, but with an 'int' instead of 'str')

The Fix: Add the * operator for multiplication.

Correct Code:

x = 10
y = 5

result = x * (y + 2)
print(result)  # Output: 70

How to Find the Bug

1. Read the error line. It will tell you which variable is the problem.
2. Look at your code and find where you defined that variable.
3. 99% of the time, you just need to rename it to something that isn’t a Python function.

Learning to debug errors is a core skill. Check out our full Python Error Encyclopedia for more guides just like this one.