Fixing “TypeError: object is not subscriptable” in Python

TypeError: 'int' object is not subscriptable means you wrote something[...] and something was an integer, which has no items to index. The type in the quotes is the clue: it tells you what the value actually was, and that is nearly always not what you thought. The five common types that appear there each point to a specific mistake.

What subscriptable means#

Square brackets after a value — value[0], value["key"], value[1:3] — ask it for an item. Lists, tuples, strings, dictionaries and most containers support that. Numbers, None, functions and classes do not. The error says which unsupported type you used, so read it:

TypeError: 'NoneType' object is not subscriptable
TypeError: 'int' object is not subscriptable
TypeError: 'builtin_function_or_method' object is not subscriptable
TypeError: 'type' object is not subscriptable

‘NoneType’: something returned None#

The most common case. A function that was expected to return a list or dictionary returned nothing, and you indexed the nothing.

def load_config():
    config = {"debug": True}
    # forgot to return config

settings = load_config()
settings["debug"]                   # TypeError: 'NoneType' object is not subscriptable

Two other reliable sources of an unexpected None:

names = ["b", "a"]
result = names.sort()               # sort() sorts in place and returns None
result[0]                           # TypeError

match = re.search(r"\d+", "no digits here")
match[0]                            # TypeError - search returned None, nothing matched

Methods that change an object in place — sort, append, reverse, update — return None. Use sorted(names) when you want a value back. For searches and lookups that can fail, check for None before indexing.

‘int’ or ‘float’: you indexed a number#

for i in len(items):                # len returns an int; you cannot loop over it...
    ...
total = 5
total[0]                            # ...and you cannot index it either

Usually this means a name was reused. A variable that held a list earlier now holds a number:

scores = [70, 85, 90]
scores = sum(scores)                # scores is now 245
scores[0]                           # TypeError: 'int' object is not subscriptable

Give the sum a different name. When a variable’s type changes partway through a function, this error is waiting somewhere below.

‘function’, ‘method’, ‘builtin_function_or_method’: missing brackets#

text = "hello world"
text.split[0]                       # TypeError: 'builtin_function_or_method' object is not subscriptable
text.split()[0]                     # "hello" - call it first, then index the result

items = get_items                   # assigned the function, not its result
items[0]                            # TypeError: 'function' object is not subscriptable
items = get_items()

The message is telling you that you indexed the function itself rather than what it returns. Add the call brackets.

‘type’: the class, not an instance#

class Point:
    def __init__(self, x, y):
        self.coords = (x, y)

Point[0]                            # TypeError: 'type' object is not subscriptable
p = Point(1, 2)
p.coords[0]                         # 1

This also appears in type hints on old Python versions: list[int] fails on 3.8 because the built-in list was not subscriptable there. On 3.9 and later it works; on older versions use typing.List[int].

‘object’, or your own class name#

class Basket:
    def __init__(self):
        self.items = []

b = Basket()
b[0]                                # TypeError: 'Basket' object is not subscriptable

Your class does not define how indexing works. Either index the attribute that holds the data, b.items[0], or make the class subscriptable by adding a __getitem__ method:

class Basket:
    def __init__(self):
        self.items = []
    def __getitem__(self, index):
        return self.items[index]

Finding it quickly#

print(type(value), repr(value))

Put that on the line before the failing one. The type confirms what the message said; the repr shows where the value came from. Then trace backwards to where the name was last assigned. In nearly every case the fix is on that earlier line, not on the line that raised.

Where to go next#

• “object is not callable” — the mirror-image error.
• “object is not iterable” — the for-loop version.
• “unhashable type” — the dictionary-key TypeError.