We have seen that Python objects have a ‘type’:
type(5)
int
Python has two core numeric types, int for integer, and float for real number.
one=1
ten=10
one_float=1.0
ten_float=10.
Zero after a point is optional, but the Dot makes it a float.
Lets look at some operations:
tenth=one_float/ten_float
tenth
0.1
type(one)
int
type(one_float)
float
The meaning of an operator varies depending on the type it is applies to! (And on the Python version.)
print(one//ten)
0
one_float/ten_float)
0.1
print(type(one/ten))
<class ‘float’>
type(tenth)
float
The divided by operator // when applied to floats, means divide by for real numbers.
But when applied to integers, it means divide then round down:
Examples:
10//3
3
10.0/3
3.3333333333333335
10/3.0
3.3333333333333335
10//3.0
3.0
So if I have two integer variables, and I want the float division, I need to change the type first.
There is a function for every type name, which is used to convert the input to an output of the desired type.
x = float(5)
type(x)
float
10/float(3)
3.3333333333333335
I lied when I said that the float type was a real number. It’s actually a computer representation of a real number
called a “floating point number”.
Representing or perfectly would be impossible in a computer, so we use a finite amount of memory to do it.
Supplementary material:
Next: Reading - Strings