Ipython Ninjitsu

• ?docstring
• ??sourcecode
• %run
• %debug
• %autoreload
• %history
• autoformat
• %reset
• !shell commands

?docstring

Stop going to google everytime your stuck and stay in your workflow. The ipython ? is a superhero for productivity and staying on task.

        
from kedro.pipeline import Pipeline
Pipeline?

Init signature:
Pipeline(
    nodes: Iterable[Union[kedro.pipeline.node.Node, ForwardRef('Pipeline')]],
    *,
    tags: Union[str, Iterable[str]] = None,
)
Docstring:
A ``Pipeline`` defined as a collection of ``Node`` objects. This class
treats nodes as part of a graph representation and provides inputs,
outputs and execution order.
Init docstring:
Initialise ``Pipeline`` with a list of ``Node`` instances.

Args:
    nodes: The iterable of nodes the ``Pipeline`` will be made of. If you
        provide pipelines among the list of nodes, those pipelines will
        be expanded and all their nodes will become part of this
        new pipeline.
    tags: Optional set of tags to be applied to all the pipeline nodes.

Raises:
    ValueError:
        When an empty list of nodes is provided, or when not all
        nodes have unique names.
    CircularDependencyError:
        When visiting all the nodes is not
        possible due to the existence of a circular dependency.
:

Note This does jump you into a pager, a j,k or up, down to navigate, q to quit.

??sourcecode

Docstring not enough for you use case. I often run into cases where the docstring is not clear enough and I need to see the implementation for myself to see what a function does.

%run

I turned my nose up at this one, prior to seeing the famous I don't like notebooks by Joel Grus. My first snobby reaction was that developing modules and using autoreload was superior. I have since realized there is a place for %run, and it can cut down on some keystrokes to import, setup, and run even when developing in modules.

%debug

ipython comes with a post-mortem debugger, and it can be a lifesaver. If we have a long running function that runs into an error it can be a complete buzzkill.

        
def long_func():
   import time
   time.sleep(12)
   n = 12
   df = pd.Data({'a': range(n)})
   return df

long_func()

%reset

reset-ipython

%autoreload

autoreload-ipython

        
c.InteractiveShellApp.extensions = ["autoreload"]
c.InteractiveShellApp.exec_lines = ["%autoreload 2"]
c.InteractiveShellApp.exec_lines.append(
    'print("Warning: disable autoreload in ipython_config.py to improve performance.")'
)

place this in your ~/.ipython/profile_default/ipython_config.py to auto reload without needing to run the magic every time

autoformat

This is a relatively new feature to ipython. I really enjoy it, as the time that I need the most help autoformatting my code is riffing on an ad hoc analysis at the command line.

        
c.TerminalInteractiveShell.autoformatter = "black"

place this in your ~/.ipython/profile_default/ipython_config.py to autoformat with black by default

new prompt

reverse history search

Control R

Want automatic imports??

pyflyby

This article covers how I setup automatic imports in ipython