Python tip 4: comparison chaining

You can chain comparison operators arbitrarily. Apart from terser code, this also has the advantage of having to evaluate the middle expression only once.

>>> from math import factorial

# factorial function gets called twice for this example
>>> factorial(3) > 2 and factorial(3) < 10
True

# function needs to be called only once here
>>> 2 < factorial(3) < 10
True

# another example
>>> 'bat' < 'cat' < 'cater'
True

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