Argument existence by assert statement in python

Question

Is there any way to check the existence of argument of a function by assert statement?

def fractional(x) :
    assert x==None, "argument missing"    <---- is it possible here to check?
    assert type(x) == int, 'x must be integer'
    assert x > 0 , ' x must be positive '
    output = 1
    for i in range ( 1 , int(x)+1) :
        output = output*i
    assert output > 0 , 'output must be positive'
    return output 
y=3
fractional()   <----- argument missing

Answer 1

you shouldn't have to assert the existence of the argument explicitly. if the argument isn't given when you call the function, you'll get a TypeError like:

>>> def foo(x):
...     pass
...
>>> foo()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: foo() takes exactly 1 argument (0 given)
>>>

if you wanted to ensure other properties of the argument (you mentioned only existence), you could test those properties and raise exceptions if they weren't met:

>>> def foo(x):
...    if not isinstance(x, str):
...        raise ValueError("argument must be a string!")
...
>>> foo(42)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in foo
ValueError: argument must be a string!
>>>