The truth value of an array with more than one element is ambiguous. use a.any() or a.all().

For boolean arrays - and comparisons like
`<`

,
`<=`

,
`==`

,
`!=`

,
`>=`

and
`>`

on NumPy arrays return boolean NumPy arrays - you can also use the element-wise bitwise functions (and operators): np.bitwise_and (& operator)

`import numpy as np first = np.array([1, 2, 3]) second = bool(first) print(second)`

The output will be this error message:

`ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()`

The element-wise equivalent for and would be the
`np.logical_and`

function, similarly you could use
`np.logical_or`

as equivalent for or.

### Logical_and() function

`import numpy as np arr = np.array([1, 2, 3]) print(np.logical_and(arr > 1, arr < 3))`

`[False True False]`

### Logical_or() function

`import numpy as np arr1 = np.arange(5) arr2 = np.arange(5, 10) arr3 = np.array(['First', 'Second', 'Third', 'Fourth', 'Fifth']) mask = np.logical_or(arr1 >= 3, arr2 < 3) print(arr3[mask])`

`['Fourth' 'Fifth']`

`import numpy as np np1 = np.zeros((3,)) np2 = np.ones((3,)) np1 in (np1, np2) # True`

### The Truth Value of an array with more than one element is ambiguous.

`np1 in (np2, np1) ValueError Traceback (most recent call last) <gfd.py> in <module> 1 np1 in (np2, np1) ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()`

`np1 == np1 array([ True, True, True]) np1 is np1 or np1 == np1 # True np1 is np2 or np1 == np2 # False`

`any(np1 is e or np1 == e for e in (np2, np1) ValueError Traceback (most recent call last) <gfd.py> in <module> 1 any(np1 is e or np1 == e for e in (np2, np1)) ValueError: The truth value of an array with more than one element is ambiguous. Use `a.any()` or `a.all()`.The issue does not occur when == is never broadcasted.`

`np1 in (np3, np1) # True`