Usage of the “==” operator for three objects

Usage of the “==” operator for three objects

Python has chained comparisons, so these two forms are equivalent:

x == y == zx == y and y == z

except that in the first, y is only evaluated once.

This means you can also write:

0 < x < 1010 >= z >= 2

etc. You can also write confusing things like:

a < b == c is d   # Don't  do this

Beginners sometimes get tripped up on this:

a < 100 is True   # Definitely don't do this!

which will always be false since it is the same as:

a < 100 and 100 is True   # Now we see the violence inherent in the system!