'TypeError' can occur when you pass an argument of the wrong type to a built-in function. Always check the function's documentation for expected input types and validate your inputs before calling functions.

'TypeError' is a common exception in Python that arises when an operation or function receives an argument of an inappropriate type. This often occurs when using built-in functions, such as trying to concatenate a string and an integer, or passing an unsupported type to a function like len(). To avoid TypeErrors, it’s essential to consult the function's documentation to understand the expected argument types. Additionally, implement validation checks before calling functions to ensure that the arguments meet the required type constraints. For example, if you're using the sum() function, confirm that the input is an iterable containing only numerical values. You can use type checks with isinstance() to ensure that the input types are correct. If TypeErrors occur, consider using exception handling to catch them and provide user-friendly error messages or fallback behaviors. By being proactive in validating input types and understanding function requirements, you can effectively prevent TypeErrors in your Python applications.