10 Little‑Known Jupyter Tricks That Can Double Your Productivity

Variable locator: %who & %whos

List variables in the current namespace and display their type, size, and value.

import numpy as np

data = np.array([1, 2, 3])
%whos  # output: data  numpy.ndarray  (3,)  [1 2 3]

Speed judge: %timeit

Compare execution speed of code snippets. The magic command runs the expression repeatedly and reports the average time.

%timeit [i**2 for i in range(1000)]
%timeit np.square(np.arange(1000))

Using %%timeit (double percent) measures the whole cell.

Terminal connector: ! command

!ls
!pip install pandas -i https://pypi.tuna.tsinghua.edu.cn/simple
!cat data.csv

Code exporter: %%writefile

%%writefile my_utils.py

def clean_data(df):
    return df.dropna().reset_index(drop=True)

Verify the export:

!cat my_utils.py

Syntax dictionary: ? & ??

len?
pd.DataFrame??

Shortcut keys "triple kill"

Shift + Enter – run cell and move to the next cell.

Ctrl + Enter – run cell and stay in place.

Alt + Enter – run cell and insert a new cell below.

Markdown beautifier

# Heading 1 (Report Title)
## Heading 2 (Section Title)
- 1. Data cleaning
- 2. Model training
$y = wx + b$  # linear regression formula
![Description](image_link)

Large‑note collapser

Installation for Jupyter Notebook

pip install jupyter_contrib_nbextensions
jupyter contrib nbextension install --user

Restart Jupyter and enable "Collapsible Headings" in the Nbextensions panel.

Installation for Jupyter Lab (≥3.0)

Search for "Collapsible Headings" in the Extension Manager and install.

Toggle collapse by clicking the triangle next to a heading or pressing T in command mode.

Export purifier: nbconvert + tags

Tagging

remove_input

– hide code, keep output. remove_output – hide output, keep code. remove_cell – delete the entire cell.

Export commands

# Export HTML without code cells
jupyter nbconvert --to html --TagRemovePreprocessor.remove_input_tags="{'remove_input'}" notebook.ipynb

# Export PDF (requires LaTeX)
jupyter nbconvert --to pdf --TagRemovePreprocessor.remove_cell_tags="{'remove_cell'}" notebook.ipynb

Smart prompt: Tab key

Auto‑complete variable and function names.

Show all methods of an object (e.g., df. + Tab).

Press Shift+Tab to display the function’s docstring in a tooltip.