Downside Formulation
Think about the next minimal instance the place a TypeError: 'bool' object will not be subscriptable happens:
boo = True boo[0] # or: boo[3:6]
This yields the next output:
Traceback (most up-to-date name final):
File "C:UsersxcentDesktopcode.py", line 2, in <module>
boo[0]
TypeError: 'bool' object will not be subscriptable
Answer Overview
Python raises the TypeError: 'bool' object will not be subscriptable when you use indexing or slicing with the sq. bracket notation on a Boolean variable. Nevertheless, the Boolean sort will not be indexable and you can not slice it—it’s not iterable!
In different phrases, the Boolean class doesn’t outline the __getitem__() methodology.
boo = True boo[0] # Error! boo[3:6] # Error! boo[-1] # Error! boo[:] # Error!
You may repair this error by
- changing the Boolean to a string utilizing the
str()perform as a result of strings are subscriptable, - eradicating the indexing or slicing name,
- defining a dummy
__getitem__()methodology for a customized “Boolean wrapper class”.
🌍 Associated Tutorials: Try our tutorials on indexing and slicing on the Finxter weblog to enhance your expertise!
Technique 1: Convert Boolean to a String
If you wish to entry particular person characters of the “Boolean” strings "True" and "False", contemplate changing the Boolean to a string utilizing the str() built-in perform. A string is subscriptable so the error is not going to happen when making an attempt to index or slice the transformed string.
boo = True boo_string = str(boo) print(boo_string[0]) # T print(boo_string[1:-1]) # ru
Technique 2: Put Boolean Into Checklist
A easy approach to resolve this error is to place the Boolean into a listing that’s subscriptable—that’s you need to use indexing or slicing on lists that outline the __getitem__() magic methodology.
bools = [True, True, True, False, False, False, True, False] print(bools[-1]) # False print(bools[3:-3]) # [False, False]
Technique 3: Outline the __getitem__() Magic Technique
You can even outline your personal wrapper sort across the Boolean variable that defines a dunder methodology for __getitem__() so that each indexing or slicing operation returns a specified worth as outlined within the dunder methodology.
class MyBool:
def __init__(self, boo):
self.boo = boo
def __getitem__(self, index):
return self.boo
my_boolean = MyBool(True)
print(my_boolean[0])
# True
print(my_boolean[:-1])
# True
This hack is mostly not really helpful, I included it only for comprehensibility and to show you one thing new. 😉
Abstract
The error message “TypeError: 'boolean' object will not be subscriptable” occurs when you entry a boolean boo like a listing resembling boo[0] or boo[1:4]. To unravel this error, keep away from utilizing slicing or indexing on a Boolean or use a subscriptable object resembling lists or strings.
Whereas working as a researcher in distributed programs, Dr. Christian Mayer discovered his love for instructing pc science college students.
To assist college students attain increased ranges of Python success, he based the programming schooling web site Finxter.com. He’s writer of the favored programming e-book Python One-Liners (NoStarch 2020), coauthor of the Espresso Break Python collection of self-published books, pc science fanatic, freelancer, and proprietor of one of many high 10 largest Python blogs worldwide.
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