Consider the following minimal example where a
TypeError: 'float' object is not subscriptable occurs:
variable = 42.42 x = variable
This yields the following output:
Traceback (most recent call last): File "C:\Users\xcent\Desktop\code.py", line 2, in <module> x = variable TypeError: 'float' object is not subscriptable
Python raises the
TypeError: 'float' object is not subscriptable if you use indexing or slicing with the square bracket notation on a float variable that is not indexable.
However, the float class doesn’t define the
variable = 1.23 variable # TypeError! variable[1:10] # TypeError! variable[-1] # TypeError!
You can fix this error by
- converting the float to a string using the
str()function because strings are subscriptable,
- removing the indexing or slicing call,
- defining a dummy
__getitem__()method for a custom float wrapper class.
Method 1: Convert Float to a String
If you want to access individual digits of the float value, consider converting the float to a string using the
str() built-in function. A string is subscriptable so the error will not occur when trying to index or slice the converted string.
variable = 42.42 my_string = str(variable) print(my_string) # 4 print(my_string[1:4]) # 2.4 print(my_string[:-1]) # 42.4
Method 2: Put Float Into List
A simple way to resolve this error is to put the float into a list that is subscriptable—that is you can use indexing or slicing on lists that define the
__getitem__() magic method.
variable = [42.42] x = variable print(x) # 42.42
Or another example with multiple float values—now it starts to actually make sense:
sensor = [1.2, 2.1, 3.2, 0.9, 4.2] print(sensor) # 1.2 print(sensor[-1]) # 4.2 print(sensor[:]) # [1.2, 2.1, 3.2, 0.9, 4.2]
Method 3: Define the __getitem__() Magic Method
class MyFloat: def __init__(self, f): self.f = f def __getitem__(self, index): return self.f my_float = MyFloat(42.42) print(my_float) # 42.42 print(my_float) # 42.42
This hack is generally not recommended, I included it just for comprehensibility and to teach you something new. 😉
The error message “
TypeError: 'float' object is not subscriptable” happens if you access a float
f like a list such as
f. To solve this error, avoid using slicing or indexing on a float but use a subscriptable object such as lists or strings.
While working as a researcher in distributed systems, Dr. Christian Mayer found his love for teaching computer science students.
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