for i in myList:
  result=isinstance(i, int)
  if result == False:
    break

>>> my_list = [1, 2, 3.25]
>>> all(isinstance(item, int) for item in my_list)
False

>>> other_list = range(3)
>>> all(isinstance(item, int) for item in other_list)
True
>>>

any(not isinstance(x, int) for x in l)

>>> any(not isinstance(x, int) for x in [0,12.])
True
>>> any(not isinstance(x, int) for x in [0,12])
False

all(isinstance(x,int) for x in l)

In [1]: a = [1,2,3]

In [2]: all(type(item)==int for item in a)
Out[2]: True

int_list = [int(x) for x in int_list]

for i, n in enumerate(int_list):
    int_list[i] = int(n)

def is_int(x):
    if type(x) == int:
        return True
    return


def all_int(a):
    for i in a:
        if not is_int(i):
            return False
    return True

all_int(my_list) # returns boolean

lst = [1,2,3]
lst2 = [1,2,'3']

list_is_int = lambda lst: [item for item in lst if isinstance(item, int)] == lst

print list_is_int(lst)
print list_is_int(lst2)

suxmac2:~$ python2.6 xx.py
True
False

all(i.isdigit() for i in myList)

>>> myList=['1', '2', '3', '150', '500', '6']
>>> all(i.isdigit() for i in myList)
True

>>> myList2=['1.5', '2', '3', '150', '500', '6']
>>> all(i.isdigit() for i in myList2)
False