IPyWalrus is a simple IPython (Jupyter) extension which enables you to use the walrus
operator (PEP 572 - Assignment Expressions) :=
for usual assignments in IPython or Jupyter.
This part of the PEP:
There are a few places where assignment expressions are not allowed, in order to avoid ambiguities or user confusion:
Unparenthesized assignment expressions are prohibited at the top level of an expression statement. Example:
y := f(x) # INVALID
(y := f(x)) # Valid, though not recommended
This rule is included to simplify the choice for the user between an assignment statement and an assignment expression -- there is no syntactic position where both are valid.
is completely valid but my IPython sessions of Jupyter notebooks are full of cells like this one:
and because it does not work in pure Python
I've prepared a small extension which makes it work:
Install the extension from pip or download the ipywalrus.py and put it somewhere in PYTHONPATH:
# pip install ipywalrus
and load it in IPython or Jupyter
%load_ext ipywalrus
If you want to enable this extension permamently, create a default profile (if you don't have one already) ipython profile create and then add ipywalrus to the list of extensions in ~/.ipython/profile_default/ipython_config.py.
MIT