Default parameter in function

you can set its default value when you define a function

def power(x, n=2):
    s = 1
    while n > 0:
        n = n - 1
        s = s * x
    return s

Note: the Mandatory parameter sshould placed in front of the default parameters

Variable parameter

if you add a star * in front of the parameter, this paramtere could be a list of tuple though you may not give it in the list form

def calc(*numbers):
    sum = 0
    for n in numbers:
        sum = sum + n * n
    return sum
calc(1,2,3)

Recursive function

def factorial(x):
    if x==1:
        return 1
    else:
        return x*factorial(x-1)

Slice

exactly like the function of : in matlab

L=list(range(100))
L[1:10]

List Comprehensions

powerful weapon
you can use it to generate list with the help of for loop

[x*(x-1) for x in range(100) if x%2==0]

Generator