AttributeError: 'NoneType' object has no attribute 'attrs' code example

Example 1: 'NoneType' object has no attribute 'attname'

super().__init__(*args, **kwargs)

Example 2: AttributeError: 'NoneType' object has no attribute 'format'

print "{} World".format('Hello')

Example 3: AttributeError: 'list' object has no attribute 'dtypes'

data = np.array(data, dtype=np.float32)