Finding the index of an item in a list

Reference: Data Structures > More on Lists Caveats follow Note that while this is perhaps the cleanest way to answer the question as asked, index is a rather weak component of the list API, and I can’t remember the last time I used it in anger. It’s been pointed out to me in the comments that because this answer is heavily … Read more

Python – TypeError: ‘int’ object is not iterable

Your problem is with this line: It tries to take cow[n], which returns an integer, and make it a list. This doesn’t work, as demonstrated below: Perhaps you meant to put cow[n] inside a list: See a demonstration below: Also, I wanted to address two things: Your while-statement is missing a : at the end. It is considered very dangerous to … Read more

IndexError: list index out of range and python

If you have a list with 53 items, the last one is thelist[52] because indexing starts at 0. IndexError Attribution to Real Python: Understanding the Python Traceback – IndexError The IndexError is raised when attempting to retrieve an index from a sequence (e.g. list, tuple), and the index isn’t found in the sequence. The Python … Read more

Understanding slice notation

It’s pretty simple really: There is also the step value, which can be used with any of the above: The key point to remember is that the :stop value represents the first value that is not in the selected slice. So, the difference between stop and start is the number of elements selected (if step is 1, the default). The other feature is that start or stop may be a negative number, which … Read more