Handling 'list index out of range' when dynamically creating a nested list in Python 3.10
Hey everyone, I'm running into an issue that's driving me crazy. Hey everyone, I'm running into an issue that's driving me crazy. I'm working on a project and hit a roadblock. I'm working with a frustrating scenario while trying to dynamically create a nested list in Python 3.10. The goal is to create a 2D list (a list of lists) where each sublist is meant to hold integers based on user input. However, I'm running into a 'list index out of range' behavior when trying to append values to the sublists. Here's a snippet of the code I have so far: ```python num_rows = 3 # Number of sublists nested_list = [[] for _ in range(num_rows)] for i in range(num_rows): for j in range(2): # Trying to add 2 elements per sublist value = i * 10 + j nested_list[i].append(value) print(nested_list) ``` When I run this, I expect to see `[[0, 1], [10, 11], [20, 21]]`, but instead, I get an `IndexError: list index out of range` behavior. I've checked the index values and I believe they are in the correct range, so I'm puzzled by this behavior. I've also tried using different approaches, such as initializing the nested list with pre-filled values or checking the length of each sublist before appending, but the behavior continues. Here’s an alternative I attempted: ```python nested_list = [] for i in range(num_rows): nested_list.append([]) for j in range(2): value = i * 10 + j nested_list[i].append(value) ``` This also runs into the same scenario. I've searched through the Python documentation and various forums but haven't found a solution. It seems like there’s something fundamental I’m missing here. Any insights or suggestions would be greatly appreciated! I'm working on a CLI tool that needs to handle this. Thanks for your help in advance! I'm working with Python in a Docker container on Debian.