When programming, there are "assumptions that must hold true if the program is working correctly," such as "the variable at this point must definitely be a positive value" or "the contents of the list ...

# [index](https://colab.research.google.com/github/CentreForDigitalHumanities/programming-in-python/blob/main/lessons/00%20index.ipynb) # Previous module: [4. Data ...