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If you have a list with 53 items, the last one is
thelist[52]
because indexing starts at 0.
From
Real Python: Understanding the Python Traceback -
IndexError
:
IndexError
The
IndexError
is raised when you attempt to retrieve an index from a sequence, like a
list
or a
tuple
, and the index isn’t found in the sequence. The Python documentation defines when this exception is raised:
Raised when a sequence subscript is out of range. (
Source
)
Here’s an example that raises the
IndexError
:
test = list(range(53))
test[53]
---------------------------------------------------------------------------
IndexError Traceback (most recent call last)
<ipython-input-6-7879607f7f36> in <module>
1 test = list(range(53))
----> 2 test[53]
IndexError: list index out of range
The error message line for an IndexError
doesn’t give you great information. You can see that you have a sequence reference that is out of range
and what the type of the sequence is, a list
in this case. That information, combined with the rest of the traceback, is usually enough to help you quickly identify how to fix the issue.
You are trying to access an element of the list that does not exist.
MyList = ["item1", "item2"]
print MyList[0] # Will work
print MyList[1] # Will Work
print MyList[2] # Will crash.
Have you got an off-by-one error?
The way Python indexing works is that it starts at 0, so the first number of your list would be [0]. You would have to print[52], as the starting index is 0 and
therefore line 53 is [52]
.
Subtract 1 from the value and you should be fine. :)
Always keep in mind when you want to overcome this error, the default value of indexing and range starts from 0, so if total items is 100 then l[99] and range(99) will give you access up to the last element.
whenever you get this type of error please cross check with items that comes between/middle in range, and insure that their index is not last if you get output then you have made perfect error that mentioned above.
If you read a list from text file, you may get the last empty line as a list element.
You can get rid of it like this:
list.pop()
for i in list:
i[12]=....