I'm making a small program for math (no particular reason, just kind of wanted to) and I ran into the error "TypeError: 'NoneType' object is not subscriptable.
I have never before seen this error, so I have no idea what it means.
import math
print("The format you should consider:")
print str("value 1a")+str(" + ")+str("value 2")+str(" = ")+str("value 3a ")+str("value 4")+str("\n")
print("Do not include the letters in the input, it automatically adds them")
v1 = input("Value 1: ")
v2 = input("Value 2: ")
v3 = input("Value 3: ")
v4 = input("Value 4: ")
lista = [v1, v3]
lista = list.sort(lista)
a = lista[1] - lista[0]
list = [v2, v4]
list = list.sort(list)
b = list[1] = list[0]
print str(a)+str("a")+str(" = ")+str(b)
The error:
Traceback (most recent call last):
File "C:/Users/Nathan/Documents/Python/New thing", line 16, in <module>
a = lista[1] - lista[0]
TypeError: 'NoneType' object is not subscriptable
lista = list.sort(lista)
This should be
lista.sort()
The .sort()
method is in-place, and returns None. If you want something not in-place, which returns a value, you could use
sorted_list = sorted(lista)
Aside #1: please don't call your lists list
. That clobbers the builtin list type.
Aside #2: I'm not sure what this line is meant to do:
print str("value 1a")+str(" + ")+str("value 2")+str(" = ")+str("value 3a ")+str("value 4")+str("\n")
is it simply
print "value 1a + value 2 = value 3a value 4"
? In other words, I don't know why you're calling str on things which are already str.
Aside #3: sometimes you use print("something")
(Python 3 syntax) and sometimes you use print "something"
(Python 2). The latter would give you a SyntaxError in py3, so you must be running 2.*, in which case you probably don't want to get in the habit or you'll wind up printing tuples, with extra parentheses. I admit that it'll work well enough here, because if there's only one element in the parentheses it's not interpreted as a tuple, but it looks strange to the pythonic eye..