Final answer:
The %timeit command in IPython is a magic function used to measure the execution time of Python code, helping to identify performance bottlenecks by executing the code multiple times to calculate an average time.
Step-by-step explanation:
The %timeit command in IPython is used to measure the execution time of a single statement or a series of statements. It is a magic command that provides timing information for Python code, which can be helpful for optimization by identifying performance bottlenecks. When you run %timeit, it executes the statement multiple times to compute an average runtime. It automatically determines the number of repetitions to get robust results. An example of using %timeit would be %timeit [expression], where expression is the Python code you wish to measure.