﻿Return the number of items in a list.

mylist = ["apple", "banana", "cherry"]
x = len(mylist)

print(x)

3

round() is a built-in function in Python. It returns x rounded to n digits from the decimal point
print ("round(70.23456) : ", round(70.23456))
print ("round(56.659,1) : ", round(56.659,1))
print ("round(-100.000056, 3) : ", round(-100.000056, 3))

round(70.23456) :  70
round(56.659,1) :  56.7
round(-100.000056, 3) :  -100.0

The abs() method returns the absolute value of x i.e. the positive distance between x and zero.
print ("abs(-45) : ", abs(-45))
print ("abs(100.12) : ", abs(100.12))

abs(-45) :  45
abs(100.12) :  100.12