I'd like to check if variable is None or numpy.array. I've implemented check_a
function to do this.
def check_a(a):
if not a:
print "please initialize a"
a = None
check_a(a)
a = np.array([1,2])
check_a(a)
But, this code raises ValueError. What is the straight forward way?
ValueError Traceback (most recent call last)
<ipython-input-41-0201c81c185e> in <module>()
6 check_a(a)
7 a = np.array([1,2])
----> 8 check_a(a)
<ipython-input-41-0201c81c185e> in check_a(a)
1 def check_a(a):
----> 2 if not a:
3 print "please initialize a"
4
5 a = None
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()
You can see if object has shape or not
def check_array(x):
try:
x.shape
return True
except:
return False
To stick to ==
without consideration of the other type, the following is also possible.
type(a) == type(None)
If you are trying to do something very similar: a is not None
, the same issue comes up. That is, Numpy complains that one must use a.any
or a.all
.
A workaround is to do:
if not (a is None):
pass
Not too pretty, but it does the job.
Source: Stackoverflow.com