[FIXED] Why Piecewise() isn't being displayed properly by IPython.display.display()?

Issue

from IPython.display import display as mathPrint
from sympy import *

x = symbols("x")

mathPrint(Eq(abs(x), Piecewise((-x, x < 0), (0, x == 0), (x, x > 0)), evaluate=False))

It's printing the expression like this:

It isn't showing the 2nd condition of the function which should be 0 for x = 0.

How can I get the desired output? Should I need to use any other display function?

Solution

There are two problems. The first is that you are passing evaluate=False to Eq rather than to Piecewise (check the brackets carefully). The second problem is that you are passing th condition x == 0 which simply evaluates to False. To make a symbolic representation of an equality you should use Eq. In that case evaluate=False is not even needed (in this example):

In [145]: Piecewise((-x, x < 0), (0, Eq(x, 0)), (x, x > 0))
Out[145]: 
⎧-x  for x < 0
⎪             
⎨0   for x = 0
⎪             
⎩x   for x > 0

Answered By - Oscar Benjamin