The “must have equal len keys and value when setting with an iterable” error occurs when you try to assign an iterable object (such as a list or a tuple) as the keys of a dictionary while the length of the keys and the length of the values are not equal. The dictionary expects that the number of keys and the number of values should be the same for each item in the iterable.
Here is an example that demonstrates this error:
my_keys = ['one', 'two', 'three']
my_values = [1, 2]
my_dict = dict(zip(my_keys, my_values))
In the above example, the length of the keys is 3, but the length of the values is only 2. Consequently, attempting to create a dictionary using the dict() function with the zip() function will raise the “must have equal len keys and value when setting with an iterable” error.
To resolve this error, you need to ensure that the lengths of your keys and values are the same. Here is an updated example:
my_keys = ['one', 'two', 'three']
my_values = [1, 2, 3]
my_dict = dict(zip(my_keys, my_values))
In this corrected example, both the lengths of the keys and values are equal. Thus, the zip() function will return an iterable of tuples, which can be successfully passed as arguments to the dict() function to create a dictionary without raising the error.