Why is bool(float("nan")) == True?

[philipyip]

The bool class can be used to type cast a string into a bool. An empty string will return False:

empty_string = ''
bool(empty_string)

A non-empty string returns True:

non_empty_string = 'nan'
bool(non_empty_string)

The bool class can be used to type cast a float into a bool. A float of value 0.0 will return False:

bool(0.0)

Any other float returns True:

bool(0.1)
bool(float('nan'))

And the following is True:

float('nan') != 0.0