More on the IPython System

Which keyboard shortcut in the IPython terminal is used to perform a readline-style reverse history search for commands based on partial matching?

What is the primary function of the `%timeit` magic command in IPython?

In an IPython session, how can you execute a shell command, such as `ls`, and store its standard output into a Python variable named `file_list`?

Which magic command invokes the postmortem debugger in IPython right after an exception has occurred?

What is the purpose of IPython's directory bookmark system, accessed via the `%bookmark` magic command?

In an IPython session, if you execute a command at line `In [27]`, what variable would you use to access the text of the *input* command itself?

Which magic command is used to execute a preformatted block of Python code from the clipboard in the IPython shell, using a special prompt for pasting?

What is the effect of running a Python script with the `%run -i` option in IPython?

According to the code design tips, why is it generally better to avoid putting all interactive-use code inside a `main()` function that is called via an `if __name__ == '__main__'` block?

What is the function of IPython's special `dreload()` function for managing module dependencies?

Which terminal command is used to create the default IPython configuration file (`ipython_config.py`) if it does not already exist?

When profiling an entire script from the command line using `cProfile`, what argument is recommended to sort the output by cumulative time spent in each function, making it easier to identify performance bottlenecks?

What is the key difference between the `%prun` and `%lprun` magic commands for profiling code in IPython?

When interrupting a running code block in IPython, pressing Ctrl-C raises a `KeyboardInterrupt`. In which scenario described in the text might this interruption not happen immediately?

Which magic command would you use to delete a variable named `my_large_df` and attempt to clear all references to its object from within IPython's internal machinery, which is useful for managing memory with large datasets?

In a profiling output from cProfile, a function call to `linalg.py:702(eigvals)` shows 100 calls, a `tottime` of 0.003, and a `cumtime` of 0.586. What does the `cumtime` represent?

What is the result of using the `%pdb` magic command in IPython?

How do you substitute the value of a Python variable `foo` into a shell command executed from IPython?

Which command-line debugger command is used to execute the current line and advance to the next line at the current level, stepping *over* any function calls?

What is the term for special commands in IPython that are prefixed by the percent symbol `%` and are designed to facilitate common tasks?

In the line profiler output, `%lprun -f add_and_sum add_and_sum(x, y)`, the line `added = x + y` took 36510 units of time, which was 79.5 percent of the total time. The line `summed = added.sum(axis=1)` took 9425 units. What percentage of the total time did the `summed` line take?

Which magic command displays detailed documentation for all available magic commands in IPython?

What is the keyboard shortcut to clear the terminal screen in IPython?

In a Jupyter notebook, what is the function of the `%load` magic command?

What does the `%reset` magic command do in an IPython session?

When using the `%run -d` command to debug a script, what must you immediately type to step into the script's execution?

What is the code design principle, mentioned as part of the Zen of Python, that is recommended for developing code for interactive use to make it easier to test and debug?

Which terminal command generates a default configuration file for a Jupyter notebook?

What is the purpose of the `-b` flag when using the `%run` command with the debugger, for example `%run -d -b2 script.py`?

In a timing comparison, `%timeit x.startswith(y)` ran 1,000,000 loops with a best time of 267 ns per loop. In contrast, `%timeit x[:3] == y` ran 10,000,000 loops with a best time of 147 ns per loop. How much faster is one loop of the slicing comparison (`x[:3] == y`) than one loop of the `startswith` method?

Which magic command is part of the `line_profiler` extension and is used for 'micro' profiling of individual functions line-by-line?

What is the function of the `%alias` magic command in IPython?

When you use a magic function like `%pwd` and assign its result to a variable (`foo = %pwd`), what happens?

Which magic command would you use to print the command input history of your IPython session?

What is the primary difference in behavior between IPython directory bookmarks (created with `%bookmark`) and command aliases (created with `%alias`) regarding session persistence?

When examining a variable `a` in the IPython debugger, why might you need to type `!a` instead of just `a`?

Which magic command is described as useful for getting a quick answer to the question, 'Why did that code block take so long to run?' in a Jupyter notebook by profiling an entire cell?

According to the code design tips, what is a potential downside of working with many small, interconnected files compared to fewer, longer files during interactive development with IPython?

How can you launch IPython with a specific, non-default profile named 'secret_project'?

In the IPython debugger, what is the function of the `l(ist)` command?

Which magic command displays a list of variables defined in the interactive namespace, with varying levels of information and verbosity?

What is the function of the semicolon (;) in an IPython input line?

Which keyboard shortcut in the IPython terminal deletes text from the cursor until the end of the line?

Why might you need to load the `line_profiler` extension using `%load_ext line_profiler`?

In the debugger, what is the function of the `w(here)` command?

What is the key reason provided for why tracing the execution time of each line with `%lprun` can significantly alter profile results if used on functions that are not of interest?

Which magic command would you use to change the current working directory to a path stored in a bookmark named `py4da`?

What is the purpose of the `automagic` feature in IPython?

When you start IPython normally, without specifying a profile, which profile is loaded by default?

In a comparison of two methods for selecting strings, method1 took 52.1 ms (Wall time) and method2 took 64.8 ms (Wall time). Which magic command was used to get these single-run execution times?