python: how to identify if a variable is an array or a scalar

I have a function that takes the argument NBins. I want to make a call to this function with a scalar 50 or an array [0, 10, 20, 30]. How can I identify within the function, what the length of NBins is? or said differently, if it is a scalar or a vector?

I tried this:

    >>> N=[2,3,5]
    >>> P = 5
    >>> len(N)
    >>> len(P)
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    TypeError: object of type 'int' has no len()

As you see, I can't apply len to P, since it's not an array.... Is there something like isarray or isscalar in python?


    >>> isinstance([0, 10, 20, 30], list)
    >>> isinstance(50, list)

To support any type of sequence, check collections.Sequence instead of list.

note : isinstance also supports a tuple of classes, check type(x) in (..., ...) should be avoided and is unnecessary.

You may also wanna check not isinstance(x, (str, unicode))