Extract only numbers from data in Jython

Question

Here is my problem. I'm working on a Jython program and I have to extract numbers from a PyJavaInstance:

[{string1="foo", xxx1, xxx2, ..., xxxN, string2="bar"}]

(where xxx are the floating point numbers).

My question is how can I extract the numbers and put them in a more simple structure like a python list.

Thank you in advance.

Answer 1

A PyJavaInstance is a Jython wrapper around a Java instance; how you extract numbers from it depends on what it is. If you need to get a bunch of stuff - some of which are strings and some of which are floats, then:

float_list = []
for item in instance_properties:
    try:
        float_list.append(float(item))
    except ValueError:
        pass

Answer 2

can you iterate and check whether an item is float? The method you're looking for is isinstance. I hope it's implemented in Jython.

Answer 3

Thank you Vinay. It's also the kind of solution I've just found:

 new_inst=[]
for element in instance:
    try:
        float(element)
        new_inst.append(float(element))
    except ValueError:
        del(element)

@SilentGhost: Good suggestion. The issue was to find what method could determine if each element I iterate is a float number.