Python: How can I check if a list contain a numeric value and return a boolean?-CodePudding

So lets say i have two lists

list1 = [1, "x", 3, "y", 5]

list2 = ["x", "y", "x", "y"]

I would like a function that returns a boolean True for list1 because it contains a few ints and a boolean False for list2 because it contains only strings.

CodePudding user response：

def is_not_all_strings(lst):
    return not all(isinstance(k,str) for k in lst)

Or, depending on the need:

def contains_an_integer(lst):
    return any(isinstance(k,int) for k in lst)

CodePudding user response：

If you want to capture all kinds of numeric values, not just integers, you can use numbers.Number, like this:

import numbers

def has_numbers(items):
    return any(isinstance(item, numbers.Number) for item in items)

This will detect not just integers but also floats, decimals, fractions etc.

CodePudding user response：

def contains_num(l):
    return any(list(map(lambda x:isinstance(x,int),l)))

CodePudding user response：

Use a for loop. That way, you can return True once you find one integer and avoid iterating through the remaining elements.

def foo(lst):
    for x in lst:
        if isinstance(x, int):
            return True
    return False