How can i define function its parameter for in each case?

Question

for example abs()
abs(-5) = abs(5) = 5
abs( [ -1, 2, -3] ) = [1, 2, 3]

how can i define my function like abs function ? ? ? I need to use it.

i hope to use it

def myFunc()
'''not yet implement... :<'''

myFunc(50) = some value

lst = [10, 20, 30]
myFunc(lst) = list of calculated values

very difficult for me...

Answer 1

>>> def my_abs(a):
if type(a) is list:
return [my_abs(i) for i in a]
else:
return a if a>0 else -a

>>> my_abs(3)
3
>>> my_abs(0)
0
>>> my_abs(-1)
1
>>> my_abs([1, -2, -7, 3])
[1, 2, 7, 3]

Answer 2

You can also make it work for any iterable object:

>>> def my_abs(a):
try:
return [my_abs(i) for i in a]
except TypeError:
return a if a>0 else -a

>>> my_abs(3)
3
>>> my_abs(-1)
1
>>> my_abs(0)
0
>>> my_abs([1, -2, -7, 3])
[1, 2, 7, 3]
>>> my_abs((1, -2, -7, 3))
[1, 2, 7, 3]
>>> my_abs(range(-3, 3))
[3, 2, 1, 0, 1, 2]