Lambda, Map, and Filter

Lambda functions are small anonymous functions defined with the lambda keyword. They can take any number of arguments but can only have one expression. Lambdas are useful for short, simple functions that are used only once, often as arguments to higher-order functions. The map() function applies a given function to all items in an input iterable and returns an iterator. It's often used with lambda functions to transform data. The filter() function constructs an iterator from elements of an iterable for which a function returns true. It's used to filter data based on a condition. Both map() and filter() return iterators, which can be converted to lists or other collections. These functional programming tools allow writing more concise and expressive code, though list comprehensions often provide a more Pythonic alternative for simple cases. Understanding these functions is important for functional programming patterns in Python and for working with code that uses these patterns.