This article will go through the various ways to deal with an unhashable type list. These are generally caused by a type being incorrectly assigned, usually because it has been included in a list of other types.
It is important to review the lists and look for mismatched or misunderstood types.
Different programs use different symbols to indicate arrays, sets, strings etc., so it is possible that a programmer typed one symbol when they should have used another.
There may be an error in mathematical logic where some operations were applied to wrong sets of data; perhaps one set was added instead of multiplied.
If this happens there will be no indication in code; debugging may be necessary to find out what has gone wrong.
Here are some points discussed about How to deal with unhashable type list–
1. What is an unhashable type list?
An unhashable type list is a type list which does not have a hash code. Hash code is a number that has been assigned to a type to signify the size of the array of each element in the array.
This method is used so that programs can locate data by their hash codes. For example, you might use “hashcode” to obtain the hashcode for “A”.
If you do not know how many elements are in your type list the program will not be able to locate any data using this technique.
2. Why is an unhashable type list important?
Using information stored in an unhashable type list may lead to errors in your program. Some of the most important points are as follows.
The length of an array will be missing if you are trying to sort items of that type.
You will have to use sublists or subarrays if you are attempting to print data for that type of data list.
You will not be able to link certain data items with each other because your program will not know how many elements there are in your type list and therefore cannot determine the amount of memory needed to store them all.
3. How to identify an unhashable type list?
An unhashable type list can be identified with the following method.
Find out if the data that you are trying to store is being used in a number of different ways. If it is, these are all kinds of lists which are very useful for your program.
But, this will not always be so so you need to take care where you decide to stash this information.
4. How to get rid of an unhashable type list?
Some different ways to get rid of an unhashable type list are discussed below.
As already mentioned, you can store it in a list which cannot be of a string nature.
This will make the hash coding disappear. But this has some disadvantages too because of course, you will not be able to use a program of this nature for a variety of purposes.
Getting rid of an unhashable type list is possible by changing the structure or format or content on which you wish to base your type on.
This will have its own implications on the rest of your program so careful planning is necessary before making any changes for this reason.
5. What are the different ways to use an unhashable type list?
An unhashable type list is used in the same way as any other list except that you will not be able to use it for sorting out items within the array.
This means that if you need to sort out strings, letters, integers etc. you will have no method of doing this.
You will need to store your information in separate sublists or subarrays depending on your needs. The best way to sort out data is by using a system which has already been set up for this purpose.
6. How to convert an unhashable type into a hashable type?
To use an unhashable list, you must first convert it into a hashable type by manually making changes in your data structure.
The following steps can be used to do this.
a) Add the unhashable list (or any other type of list) to another hashable one by adding or appending the data elements of the original list.
b) Check whether your list will fit in the allocated memory.
c) If Yes, proceed with step 6d otherwise, go on with step 6e.
d) Add or append the rest of the data elements using proper manipulations while maintaining their order while checking if they will fit in memory.
