TypeError: 'str' object is not callable — how to fix

Traceback (most recent call last):
  File "main.py", line 4, in <module>
    print(str(42))
TypeError: 'str' object is not callable

Quick fix: Find where the name was reassigned (e.g. str = "...", input = input()), rename that variable, and restart the interpreter/kernel (del str in a notebook). Use s[0] not s(0) for indexing, and "..." % x or f-strings, not "..."(x).

What it means

x() calls x. When x is a string, Python raises TypeError: 'str' object is not callable. Look at the line in the traceback and ask, for every name( on it: is name actually a string right now?

print(type(str), type(input))   # should be <class 'type'> / builtin_function_or_method

Cause 1: a variable shadows the str built-in

str = "hello"
...
label = str(42)      # TypeError: 'str' object is not callable

Rename the variable (text, s, name...). In Jupyter or an interactive shell, the bad assignment persists even after you edit the cell — undo it:

del str          # restores the built-in

or restart the kernel.

The same happens with other built-ins: input, format, type, id, print (print = "x"), max, sum. A classic:

input = input("Name: ")
age = input("Age: ")     # TypeError: 'str' object is not callable

Cause 2: an attribute or method name collides

class User:
    def __init__(self, name):
        self.name = name
    def name(self):            # replaced by the instance attribute
        return self.name

User("a").name()   # TypeError: 'str' object is not callable

The instance attribute self.name (a string) hides the method. Rename one of them (get_name), or use @property and access it without parentheses:

class User:
    def __init__(self, name):
        self._name = name
    @property
    def name(self):
        return self._name

User("a").name      # no ()

Also: calling a property with () gives the same error, e.g. response.text() in requests — .text is a string property; use response.text (but response.json() is a method).

Cause 3: parentheses instead of brackets

s = "abcdef"
s(0)        # wrong
s[0]        # 'a'

Cause 4: missing operator when formatting

msg = "Total: %d" (total)     # missing %
msg = "Hi " "there" (name)    # missing +

Fix:

msg = "Total: %d" % total
msg = f"Total: {total}"
msg = "Hi " + name

Cause 5: a function was replaced by its result

def get_title(): return "Report"
get_title = get_title()   # now a string
get_title()               # TypeError

Or a callback parameter receives a string instead of a function:

def run(callback):
    callback()

run("my_func")      # wrong: pass my_func, not its name
run(my_func)

If you need to look up a function by name, use a dict: handlers = {"save": save} then handlers[name]().

Finding the culprit fast

Search for assignments to the name:

grep -nE '^\s*(str|input|format|type)\s*=' *.py

Linters catch this too: pylint reports redefined-builtin (W0622), and ruff has rule A001 (builtin-variable-shadowing).

Last updated 2026-11-02.