Final answer:
The %prun magic command is used in IPython and Jupyter notebooks for profiling code, allowing users to assess performance by measuring time spent in functions, and count of function calls. It helps identify inefficiencies in code for optimization.
Step-by-step explanation:
The %prun magic command is used in the context of IPython and Jupyter notebooks. Its purpose is to execute a statement while measuring the execution time of various parts of the code. Specifically, %prun allows a user to run code with the Python profiler to get detailed reports on the performance, which includes the number of calls to each function, the time spent in each function, and more. This can be invaluable for identifying bottlenecks or inefficient sections of code that may need optimization. To use the command, simply precede the line of code with %prun, followed by the statement you want to profile. For more comprehensive profiling, you can pass additional arguments and options to customize the results, such as which functions to include or exclude in the report.