According to https://ipython.org/ipython-doc/3/notebook/nbconvert.html you are looking for the nbconvert command with the --to script option.

ipython nbconvert notebook.ipynb --to script

EDIT:

as per the comments, this is now updated to

jupyter nbconvert mynotebook.ipynb --to python

In short: This command-line option converts mynotebook.ipynb to python code:

jupyter nbconvert mynotebook.ipynb --to python

note: this is different from above answer. ipython has been renamed to jupyter. the old executable name (ipython) is deprecated.

More details: jupyter command-line has an nbconvert argument which helps convert notebook files (*.ipynb) to various other formats.

You could even convert it to any one of these formats using the same command but different --to option:

• asciidoc
• custom
• html
• latex. (Awesome if you want to paste code in conference/journal papers).
• markdown
• notebook
• pdf
• python
• rst
• script
• slides. (Whooh! Convert to slides for easy presentation 😊)

the same command jupyter nbconvert --to latex mynotebook.ipynb

For more see jupyter nbconvert --help. There are extensive options to this. You could even to execute the code first before converting, different log-level options etc.

you can use this to do that :

pip install ipynb-py-convert

then run this on your terminal to convert .py file to .ipynb :

ipynb-py-convert Ex/abc.py Ex/abc.ipynb

to convert .ipynb files to .py :

ipynb-py-convert Ex/abc.ipynb Ex/abc.py

You can run a .py file in the same directory:

import json

files = ["my_first_file_name.ipynb", "my_second_file_name.ipynb"]

for file in files:
    code = json.load(open(file))
    py_file = open(f"{file}.py", "w+")

    for cell in code['cells']:
        if cell['cell_type'] == 'code':
            for line in cell['source']:
                py_file.write(line)
            py_file.write("\n")
        elif cell['cell_type'] == 'markdown':
            py_file.write("\n")
            for line in cell['source']:
                if line and line[0] == "#":
                    py_file.write(line)
            py_file.write("\n")

    py_file.close()

I rewrite this code from Syrtis Major's answer.

Tested on Ubuntu 20.04

Install required packages for PIP

$ pip install ipython
$ pip install nbconvert

To install required packages

$ sudo apt-get install texlive-xetex texlive-fonts-recommended texlive-plain-generic

METHOD 1

Use jupyter nbconvert command to convert to different format

Source file pro.ipynb

• To convert to ascii

  $ jupyter nbconvert --to asciidoc pro.ipynb
  

• To convert to pdf

  $ jupyter nbconvert --to pdf pro.ipynb
  

• To convert to python

  $ jupyter nbconvert --to python pro.ipynb
  

METHOD 2

Convert ipynb project through python code use savefig method of pyplot:

pro.ipynb

import matplotlib.pyplot as plt
%matplotlib inline
exp_vals=[1400,600,300,410,250]
exp_labels=['Home Rent','Food','Phone/Internet Bill','Car','Other Utilities']
plt.axis('equal')
plt.pie(exp_vals,labels=exp_labels,radius=2,autopct='%0.1f%%',shadow=True,explode=[0,0.5,0,0.3,0],startangle=20)
# plt.show()
plt.savefig('piechart.jpg',bbox_inches='tight',pad_inches=2,transparent=True,edgecolor='r')

piechart.png image that it generated:

   Hope this helps to convert your ~(`)/\/\/\_ [Python] code

well first of all you need to install this package below:

sudo apt install ipython
jupyter nbconvert --to script [YOUR_NOTEBOOK].ipynb

two options are available either --to python or --to=python

for me this works fine:

jupyter nbconvert --to python while.ipynb 

[NbConvertApp] Converting notebook while.ipynb to python
[NbConvertApp] Writing 758 bytes to while.py

pip3 install ipython

if it does not work for you try, by pip3.

pip3 install ipython

Use VS Code

1. Step 1 : Open your .ipynb file in vs code.
2. Step 2 : Click on export Screenshot of where the option is.
3. Step 3 : Click on Python Script Screenshot of export types. Now VS Code will open your file as a python script in a new tab with an untitled name.
4. Now press Ctrl + s to save it to wherever you want.

You definitely can achieve that with nbconvert using the following command:

jupyter nbconvert --to python while.ipynb 

However, having used it personally I would advise against it for several reasons:

1. It's one thing to be able to convert to simple Python code and another to have all the right abstractions, classes access and methods set up. If the whole point of you converting your notebook code to Python is getting to a state where your code and notebooks are maintainable for the long run, then nbconvert alone will not suffice. The only way to do that is by manually going through the codebase.
2. Notebooks inherently promote writing code which is not maintainable (https://docs.google.com/presentation/d/1n2RlMdmv1p25Xy5thJUhkKGvjtV-dkAIsUXP-AL4ffI/edit#slide=id.g3d7fe085e7_0_21). Using nbconvert on top might just prove to be a bandaid. Specific examples of where it promotes not-so-maintainable code are imports might be sprayed throughout, hard coded paths are not in one simple place to view, class abstractions might not be present, etc.
3. nbconvert still mixes execution code and library code.
4. Comments are still not present (probably were not in the notebook).
5. There is still a lack of unit tests etc.

So to summarize, there is not good way to out of the box convert python notebooks to maintainable, robust python modularized code, the only way is to manually do surgery.

My version of Jupyter Notebook, 3.3.2, has this option on the File Menu:

You can use the following script to convert jupyter notebook to Python script, or view the code directly.

To do this, write the following contents into a file cat_ipynb, then chmod +x cat_ipynb.

#!/usr/bin/env python
import sys
import json

for file in sys.argv[1:]:
    print('# file: %s' % file)
    print('# vi: filetype=python')
    print('')
    code = json.load(open(file))

    for cell in code['cells']:
        if cell['cell_type'] == 'code':
            print('# -------- code --------')
            for line in cell['source']:
                print(line, end='')
            print('\n')
        elif cell['cell_type'] == 'markdown':
            print('# -------- markdown --------')
            for line in cell['source']:
                print("#", line, end='')
            print('\n')

Then you can use

cat_ipynb your_notebook.ipynb > output.py

Or show it with vi directly

cat_ipynb your_notebook.ipynb | view -

If this is a one-off, follow e.g. @kikocorreoso depending if you want to use command line or gui.

However, if you want some solution that will maintain a synchronized version of the .py and the .ipynb you really should consider using jupytext as also pointed out by @Wayne

Run conda install jupytext or pip install jupytext

Then do: jupytext --set-formats ipynb,py <file>.ipynb

To keep it synchronized to the .py file:

jupytext --set-formats ipynb,py <file>.ipynb --sync

This will make sure jupyter keeps the two files in sync when saving from now on...

Last note: If you are a gui person, after running the installation command for jupytext, everything else can be done from the gui as well File-->Jupytext-->pair Notebook with light Script:

1. Go to https://jupyter.org/
2. click on nbviewer
3. Enter the location of your file and render it.
4. Click on view as code (shown as < />)

One way to do that would be to upload your script on Colab and download it in .py format from File -> Download .py

Convert the Ipynb dir files to .py

import os

for fname in os.listdir():
    if fname.endswith('ipynb'):
        os.system(f'jupyter nbconvert {fname} --to python')

jupyter nbconvert [filename].ipynb --no-prompt --to python

The above code will generate [filename].py in the same directory

Jupytext allows for such a conversion on the command line, and importantly you can go back again from the script to a notebook (even an executed notebook). See here.

In addition to from the command line, installed Jupytext can make corresponding pairs of files automatically, and has a pre-commit hook option that you can use if you use GitHub in conjuction with your efforts. See here about the pre-commit hook.

Copy all the (''.ipynb) files in the Desired folder then execute:

import os    

desired_path = 'C:\\Users\\Docs\\Ipynb Covertor'

os.chdir(desired_path)

list_of_directory = os.listdir(desired_path)

for file in list_of_directory:
        os.system('ipython nbconvert --to script ' + str(file))

just adding my 2 cents to all the valid answers.

It is possible to create a hook on the Jupyter notebook so that every time the notebook is saved it generates/updates the python file from the notebook

First you need to generate a config

jupyter notebook --generate-config

This creates a file in /User/your-user/.jupyter/jupyter_notebook_config.py

Then you update this file with your hook

import os
from subprocess import run

def post_save(model, os_path, contents_manager, **kwargs):
    """Automatically convert .ipynb to .py using jupytext on save."""
    if model['type'] == 'notebook':
        # Run the jupytext command to convert the notebook to .py
        run(['jupytext', '--to', 'py', os_path])

c.FileContentsManager.post_save_hook = post_save

Restart the Jupyter notebook, open it, add things and save. A new file .py is generated every time you save the Jupyter notebook. I hope it is useful!